Intrathecal administration of Y-27632, a specific rho-associated kinase inhibitor, for rat neoplastic meningitis

The small GTP-binding protein Rho and its target Rho-associated kinase trigger an intracellular signaling cascade that controls actin cytoskeleton and plays an essential role in cell motility and adhesion. A specific Rho-associated kinase inhibitor, Y-27632, has been reported to inhibit cancer invasion. Clinically, disseminated tumor cells in the cerebrospinal fluid invade the intraparenchymal region, damaging the brain and nerves, resulting in fatal brain stem dysfunction, despite intrathecal chemotherapy. To expand therapeutic options for this devastating neoplastic meningitis, we evaluated the potential use of intrathecal Y-27632 administration by employing Walker 256 cells, a rat mammary cancer cell line. Y-27632 dose-dependently inhibited chemotactic and invasive activity of Walker 256 cells. Y-27632 also inhibited the phosphorylation level of regulatory myosin light chain in vitro, but the effect was temporary and was considerably diminished within 16 hours. Y-27632 induced striking morphologic changes in Walker 256 cells, as evidenced by decreased cell-matrix adhesion in culture dishes and three-dimensional collagen I gels, and slightly inhibited colony formation in soft agar. Nevertheless, this drug treatment did not affect Walker 256 cell growth rate. We were able to administer continuous delivery of this inhibitor using an osmotic pump and maintaining drug concentration of 10 mumol/L within the brain. Importantly, this concentration of Y-27632 showed minimal neurotoxicity both in vitro and in vivo. We found that an intrathecal therapy, combining 5-fluoro-2'-deoxyuridine with Y-27632, significantly increased the survival time of rats bearing meningeal carcinomatosis in comparison with animals treated with 5-fluoro-2'-deoxyuridine alone. Taken together, our findings indicate that continuous intrathecal administration of Y-27632 could be a promising therapeutic method when combined with chemotherapy for treating human neoplastic meningitis.     

A monoclonal antibody against alpha-smooth muscle actin: a new probe for smooth muscle differentiation

A monoclonal antibody (anti-alpha sm-1) recognizing exclusively alpha- smooth muscle actin was selected and characterized after immunization of BALB/c mice with the NH2-terminal synthetic decapeptide of alpha- smooth muscle actin coupled to keyhole limpet hemocyanin. Anti-alpha sm- 1 helped in distinguishing smooth muscle cells from fibroblasts in mixed cultures such as rat dermal fibroblasts and chicken embryo fibroblasts. In the aortic media, it recognized a hitherto unknown population of cells negative for alpha-smooth muscle actin and for desmin. In 5-d-old rats, this population is about half of the medial cells and becomes only 8 +/- 5% in 6-wk-old animals. In cultures of rat aortic media SMCs, there is a progressive increase of this cell population together with a progressive decrease in the number of alpha- smooth muscle actin-containing stress fibers per cell. Double immunofluorescent studies carried out with anti-alpha sm-1 and anti- desmin antibodies in several organs revealed a heterogeneity of stromal cells. Desmin-negative, alpha-smooth muscle actin-positive cells were found in the rat intestinal muscularis mucosae and in the dermis around hair follicles. Moreover, desmin-positive, alpha-smooth muscle actin- negative cells were identified in the intestinal submucosa, rat testis interstitium, and uterine stroma. alpha-Smooth muscle actin was also found in myoepithelial cells of mammary and salivary glands, which are known to express cytokeratins. Finally, alpha-smooth muscle actin is present in stromal cells of mammary carcinomas, previously considered fibroblastic in nature. Thus, anti-alpha sm-1 antibody appears to be a powerful probe in the study of smooth muscle differentiation in normal and pathological conditions.     

Establishment of embryonic cultures and somatic embryogenesis in callus culture of guggul-Commiphora wightii (Arnott.) Bhandari

Somatic embryogenesis in callus cultures of Commiphora wightii (Arnott.) Bhandari was achieved. Though the frequency of explants producing embryonic culture was low, immature zygotic embryos were the only suitable explants to produce embryonic callus after reciprocal transfers on media containing 2,4,5-trichlorophenoxy acetic acid (0.1 mgl(-1)) and kinetin (0.1 mgl(-1)) or devoid of growth regulators. All other media failed to produce embryonic callus. Embryonic cells were small, densely filled with cytoplasm and isodiametric as compared to non-embryonic cells, which were large, elongated and vacuolated. Maximum growth of embryonic callus was recorded on modified MS medium (MS-2 medium) supplemented with BA (0.25 mgl(-1)) and IBA (0.1 mgl(-1)). MS-2 salts supported higher growth of callus as compared to tissues grown on B5 medium containing same concentrations of plant growth regulators. Exogenous medium nutrients had no effect on somatic embryo development whereas plant growth regulators had little effect. Asynchronously growing embryos formed plantlets regularly which were successfully transferred to the field conditions.     

Transplacental action of sodium nitrite on embryonic cells of Syrian golden hamster

Hamster embryos were treated with various doses of NaNO2 in utero, by its oral administration to the mothers, and then the embryonic cells were examined for micronucleus formation, chromosomal aberrations, morphological or malignant transformation and drug-resistant mutations. For induction of resistant mutations, the cells were cultured in normal medium for 72 h, and then selected in media containing 8-azaguanine (10 or 20 microgram/ml) or 1 mM ouabain. This treatment with NaNO2 caused marked dose-dependent induction of 8-azaguanine- and ouabain-resistant mutations. Cultured embryonic fibroblasts in the resting state also showed a marked dose-dependent increase in micronucleus formation but not an increase in chromosomal aberrations. This treatment also caused morphological and neoplastic transformation of the cells. Transplacental oral treatment with DMN, as a positive control, caused changes of similar extent in biological effects of embryonic fibroblasts, and in addition it caused chromosomal aberrations in metaphase plates. On the contrary, transplacental oral application of NaNO2 did not induce any biological change in cultured embryonic fibroblasts.     

Stable variant of LM fibroblast defective in fluid-phase but competent in receptor-mediated endocytosis

The F-40 cell line, a stable variant of LM fibroblasts selected for its resistance to polyethylene glycol (PEG)-induced fusion (Roos and Davidson: Somatic Cell and Molecular Genetics 6:381-391, 1980), has a decreased capacity to internalize fluid-phase markers and nonspecifically surface-bound macromolecules. It is not defective in exocytosis since, after a short sucrose pulse, it releases the same fraction of ingested sucrose into the medium as does the parental line. F40 cells have a normal capacity to carry out receptor-mediated endocytosis, as tested with 125I-alpha-2 macroglobulin (alpha-2 MG) and 125I-transferrin (Tf), and to recycle Tf receptor to the cell surface. These data demonstrate that receptor-mediated and non-receptor mediated endocytosis are distinct processes that can be altered independently. Of the many membrane fusions occurring in the course of endocytosis, the only one that appears associated with the defect in cell fusion characteristic of F40 cells is the formation of primary endocytotic vesicles engaged in non-receptor-mediated internalizations.     

Regulation of purine metabolism: a comparative study of the kinetic properties of adenylosuccinate synthetases from various sources.

1. Adenylosuccinate synthetase has been partially purified from rat liver, fetal rat liver, Novikoff ascites cells, Walker carcinoma 256 solid tumors, chicken liver and muscle, rabbit muscle and pig brain. 2. Considerable differences exist in Michaelis constants among the various species and the changes possibly reflect differences in regulation. 3. The kinetic properties of the enzyme are generally consistent with proposed metabolic roles in various tissues.     

Different preparations of natural and recombinant human interleukin-6 (IFN-beta 2, BSF-2) similarly stimulate acute phase protein synthesis and uptake of alpha-aminoisobutyric acid by cultured rat hepatocytes

1. Rat hepatocytes were cultured for 2 days in Williams E medium containing 1 microM insulin and dexamethasone. 2. Production of five plasma proteins was determined by electroimmunoassay in the media, and amino acid uptake was measured by [alpha-14C]aminoisobutyric acid accumulation in hepatocytes. 3. Supernatants from rat peritoneal macrophages and IL-6/IFN-beta 2/BSF-2 obtained from four different laboratories similarly stimulated synthesis of fibrinogen, alpha 1-cysteine proteinase inhibitor and alpha 2-macroglobulin, as well as [14C]-accumulation in cultured hepatocytes. 4. It is concluded that IL-6 is the principal hepatocyte stimulating factor responsible for typical features of the acute phase response of liver cells.     

The effect of triethyllead on the motile activity of walker 256 carcinosarcoma cells

The effect of triethyllead (TriEL) on the morphology and motile activity of Walker 256 carcinosarcoma cells was investigated. It was found that both 2 and 5 microM TriEL affected the cellular motility in a dose- and time-dependent manner. Initially, 2 microM TriEL caused the formation of blebs instead of lamellipodia at the front of some cells and stimulated the migration of Walker cells, but after 2 hours of 2 microM TriEL treatment, a reduction of cellular motility was observed. In the presence of 5 microM TriEL, Walker 256 carcinosarcoma cells rounded up, and their rate of movement was reduced. Moreover, the treatment of Walker carcinosarcoma cells with TriEL caused the disruption of microtubules and affected the F-actin distribution at both concentrations. At a concentration of 2 microM TriEL, the actin staining intensity was greatest in the tail of front-tail polarised blebbing cells and the actin layer was very thin at the leading edge. The control cells showed linear cortical F-actin distribution and somewhat less intense cytoplasmic staining at the same TriEL concentration. Cells treated with 5 microM TriEL showed an under-membrane pattern of actin distribution.     

Nucleoside transport in Walker 256 rat carcinosarcoma and S49 mouse lymphoma cells. Differences in sensitivity to nitrobenzylthioinosine and thiol reagents.

The characteristics of nucleoside transport were examined in Walker 256 rat carcinosarcoma and S49 mouse lymphoma cells. In Walker 256 cells the initial rates of uridine, thymidine and adenosine uptake were insensitive to the nucleoside transport inhibitor nitrobenzylthioinosine (NBMPR) (1 microM), but were partially inhibited by dipyridamole (10 microM), another inhibitor of nucleoside transport. In contrast, the transport of these nucleosides in S49 cells was completely blocked by both inhibitors. Nucleoside transport in Walker 256 and S49 cells also differed in its sensitivity to the thiol reagent p-chloromercuribenzenesulphonate (pCMBS). Uridine transport in Walker 256 cells was inhibited by pCMBS with an IC50 (concentration producing 50% inhibition) of less than 25 microM, and inhibition was readily reversed by beta-mercaptoethanol. In S49 cells uridine transport was only inhibited at much higher concentrations of pCMBS (IC50 approximately equal to 300 microM). In other respects nucleoside transport in Walker 256 and S49 cells were quite similar. The Km and Vmax. values for uridine transport were nearly identical, and the transporters of both cell lines appeared to accept a broad range of nucleosides as substrates. Uridine transport in Walker 256 cells was non-concentrative and did not require an energy source. These studies demonstrate that nucleoside uptake in Walker 256 cells is mediated by a facilitated-diffusion mechanism which differs markedly from that of S49 cells in its sensitivity to the transport inhibitor NBMPR and the thiol reagent pCMBS.     

Cytocidal effects of human fibroblasts on HeLa cells in vitro

Cocultivation of human fibroblasts and HeLa cells in vitro leads to the development of specific patterns of growth. These patterns depend on the cell density and cell-cell ratio in the initial mixed inoculum. Human fibroblasts can cause extensive nuclear fragmentation and cellular disintegration of HeLa cells in vitro after coculture for periods longer than 10 days, without subculturing, and with medium replacement every 2 days. This phenomenon is preceded by directional locomotion of the fibroblastic population parallel to the edges of and around HeLa colonies and by overgrowth of both cell types at the border sites. A dense border is thus developed around the HeLa colonies. In the absence of refeeding every 2 days, HeLa cells can overgrow, pass the dense border and form a new zone. Refeeding at this stage can again cause the formation of a second concentric dense border around the HeLa zone. This phenomenon may represent an in vitro metaphor of the invasive property of neoplastic cells. It also points out, however, the importance of feeding for the activation of fibroblasts against HeLa cells.     

Characteristics of hematin uptake in malignant, embryonic and normal cells

The characteristics of hematin uptake were examined in three malignant cell lines [L1210 leukemia, 745 murine erythroleukemia (MEL) and Walker carcinoma (W256)], a cell line derived from normal rat liver (BRL-3A) and a normal embryonic cell, chick embryo fibroblasts (CEF). Uptake in the normal liver cell line was slight and occurred at a slow rate in contrast to the rapid uptake, which was more rapid and of greater magnitude in the three tumor cell lines, Saturation of the heme uptake mechanism was observed in MEL cells at an extra-cellular hematin concentration of 160 micro M and in L1210 cells at 300 micro M. At saturation L1210 cells achieved a cellular heme concentration nine times as high as MEL cells. Hematin uptake in MEL cells was markedly augmented by pretreatment with DMSO, procaine, detergent or proteolytic enzymes or by increases in the pH of the medium from 8 to 9.5. In contrast to MEL cells where SA inhibits growth by lowering cellular heme, the inhibition of growth of L1210 cells by SA appears to operate by a mechanism independent of heme. In gradual increase in hematin uptake capacity in MEL cells over a period of days. Afer exposure of MEL cells to a high concentration of hematin in the medium, the egress of heme was followed under various conditions. Of the various agents studied, only cyanide produced a loss of heme from MEL cells.     

Acute phase response to recombinant interleukin-6 and macrophage- and fibroblast-derived crude cytokine preparations in primary cultures of mouse hepatocytes

A number of acute phase proteins were determined by electroimmunoassay in media from CBA mouse hepatocytes cultured for 2 days with human recombinant IFN beta 2/IL-6, as well as with conditioned media from LPS-stimulated rat macrophages, and of murine L fibroblasts. It was found that human recombinant IL-6 caused three-fold increase in secretion of fibrinogen, while haptoglobin, complement C3 and transferrin were increased respectively, to 168 per cent, 151 per cent, and 145 per cent of the control. DEX(10(-7) M) in DMEM supplemented with 5 per cent FCS, enhanced the IL-6 effect on the three positive acute phase proteins. IL-6 elevated haptoglobin mRNA in mouse hepatocytes to a degree comparable with the concentration of the protein in the culture medium. The effect of conditioned media from murine fibroblasts and peritoneal rat macrophages was generally similar to that of recombinant IL-6. However, both natural preparations of the cytokines caused decrease in albumin and alpha-1-proteinase inhibitor secretion.     

Preliminary crystallographic data for NAD(P)H quinone reductase isolated from the Walker 256 rat carcinoma cell line

An NAD(P)H quinone reductase isolated from Walker rat 256 carcinoma cells has been crystallized in a form suitable for high-resolution structural analysis. The crystals belong to orthorhombic space group P2(1)2(1)2(1) with cell parameters a = 168.15 A, b = 105.09 A and c = 67.38 A and contain four monomeric or two dimeric enzyme molecules per asymmetric unit. Diffraction extends beyond 2.3 A resolution.     

N5-methyltetrahydrofolate: Homocysteine methyltransferase activity in extracts from normal,malignant and embryonic tissue culture cells

Malignant cells (J111, L1210, W-256) and human embryonic cells (FL) are unable to survive and grow when homocystine replaces methionine in tissue culture media containing excess vitamin B₁₂ and folic acid. Extracts of these same cells when grown in media containing methionine and more than adequate vitamin B₁₂ and folic acid have diminished N⁵-methyltetrahydrofolate: homocysteine methyltransferase activities in the absence of added cyanocobalamin when compared with extracts of normal cells (adult rat thymus and liver fibroblasts). Extracts of human monocytic leukemia (J111) and human amnion cells (FL) have normal enzymatic activity in the presence of added cyanocobalamin whereas the rodent malignant cells (W-256 and L1210) have abnormally low activity in the absence or presence of added vitamin B₁₂.     

Telomere Dynamics in Human Cells Reprogrammed to Pluripotency

Background

Human induced pluripotent stem cells (IPSCs) have enormous potential in the development of cellular models of human disease and represent a potential source of autologous cells and tissues for therapeutic use. A question remains as to the biological age of IPSCs, in particular when isolated from older subjects. Studies of cloned animals indicate that somatic cells reprogrammed to pluripotency variably display telomere elongation, a common indicator of cell “rejuvenation.”

Methodology/Principal Findings

We examined telomere lengths in human skin fibroblasts isolated from younger and older subjects, fibroblasts converted to IPSCs, and IPSCs redifferentiated through teratoma formation and explant culture. In IPSCs analyzed at passage five (P5), telomeres were significantly elongated in 6/7 lines by >40% and approximated telomere lengths in human embryonic stem cells (hESCs). In cell lines derived from three IPSC-teratoma explants cultured to P5, two displayed telomeres shortened to lengths similar to input fibroblasts while the third line retained elongated telomeres.

Conclusions/Significance

While these results reveal some heterogeneity in the reprogramming process with respect to telomere length, human somatic cells reprogrammed to pluripotency generally displayed elongated telomeres that suggest that they will not age prematurely when isolated from subjects of essentially any age.     

Organ and species specificity of epithelial growth

Summary Previous work in this laboratory demonstrated that rat respiratory airway epithelial cells grown from tissue explants undergo concurrent division and differentiation in culture. In the present studies, this model system has been used to optimize conditions for epithelial growth, with the goal of facilitating the culture of epithelium from other organs and species. Fibroblasts appeared to limit the expansion of epithelial outgrowths; their growth was controlled by using delipidated serum, rather than serum, in the culture media, with addition of adrenergic antagonists. In nonsupplemented media, rat tracheal fibroblasts doubled in number in about 3 d. The doubling time was slowed to more than 9 d by the serum substitution in conjunction with the α-antagonist phenoxybenzamine. Rat tracheal epithelial cultures maintained under identical conditions doubled in less than 4 d, so that a growth advantage of threefold was achieved. The combination of conditions also seemed to inhibit growth of fibroblasts from other species. However, even when the problem of fibroblast overgrowth was obviated, the respiratory airway epithelia of the mouse, hamster, and marmoset failed to show self-sustaining growth in culture. The rat epithelium continued to grow for over 6 wk. A number of other organs from the rat, notably esophagus, skin, and salivary gland, showed self-sustaining growth after removal of explants. Although epithelial outgrowths were formed by explants from certain organs of the hamster, only those from the kidney and thyroid continued to grow after removal of the tissue explants. Therefore, growth failure in cultured epithelia, quantitatively defined, is common and frequently unrelated to the problem of fibroblast overgrowth. The rat seems to be the species of choice for studies on the isolated epithelia from most organ sites. The research was sponsored jointly by Grant PCM 8110597 from the National Science Foundation, Washington, D.C., the Environmental Protection Agency under Interagency Agreement 81-D-X 0533, the National Institute of Health Requisition 375014 GPCL, and the Office of Energy Research, U.S. Department of Energy, under contract W-7405-eng-26 with the Union Carbide Corporation. A preliminary report of this work appeared in the J. Cell Biol. 91: 32a, 1981.     

The tumor microenvironment: a critical determinant of neoplastic evolution

Evolution of neoplastic cells has generally been regarded as a cumulative intrinsic process resulting in altered cell characteristics enabling enhanced growth properties, evasion of apoptotic signals, unlimited replicative potential and gain of properties enabling the ability to thrive in ectopic tissues and in some cases, ability to metastasize. Recently however, the role of the neoplastic microenvironment has become appreciated largely due to the realization that tumors are not merely masses of neoplastic cells, but instead, are complex tissues composed of both a non-cellular (matrix proteins) and a cellular 'diploid' component (tumor-associated fibroblasts, capillary-associated cells and inflammatory cells), in addition to the ever-evolving neoplastic cells. With these realizations, it has become evident that early and persistent inflammatory responses observed in or around many solid tumors, play important roles in establishing an environment suitable for neoplastic progression by providing diverse factors that alter tissue homeostasis. Using cutaneous melanoma and squamous cell carcinoma as tumor models, we review the current literature focussing on inflammatory and tumor-associated fibroblast responses as critical mediators of neoplastic progression for these malignancies.     

Multiple sclerosis: Identification and clinical evaluation of novel CSF biomarkers

Multiple sclerosis (MS) is a neuro-inflammatory and neurodegenerative disease that results in damage to myelin sheaths and axons in the central nervous system and which preferentially affects young adults. We performed a proteomics-based biomarker discovery study in which cerebrospinal fluid (CSF) from MS and control individuals was analyzed (n = 112). Ten candidate biomarkers were selected for evaluation by quantitative immunoassay using an independent cohort of MS and control subjects (n = 209). In relapsing–remitting MS (RRMS) patients there were significant increases in the CSF levels of alpha-1 antichymotrypsin (A1AC), alpha-1 macroglobulin (A2MG) and fibulin 1 as compared to control subjects. In secondary progressive MS (SPMS) four additional proteins (contactin 1, fetuin A, vitamin D binding protein and angiotensinogen (ANGT)) were increased as compared to control subjects. In particular, ANGT was increased 3-fold in SPMS, indicating a potential as biomarker of disease progression in MS. In PPMS, A1AC and A2MG exhibit significantly higher CSF levels than controls, with a trend of increase for ANGT. Classification models based on the biomarker panel could identify 70% of the RRMS and 80% of the SPMS patients correctly. Further evaluation was conducted in a pilot study of CSF from RRMS patients (n = 36), before and after treatment with natalizumab.