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Friedreich's ataxia is an incurable disease caused by frataxin (FXN) protein deficiency, which is mostly induced by GAA repeat expansion in intron 1 of the FXN gene. Here, we identified antisense oligonucleotides (ASOs), complementary to two regions within the first intron of FXN pre-mRNA, which could increase FXN mRNA by ∼2-fold in patient fibroblasts. The increase in FXN mRNA was confirmed by the identification of multiple overlapping FXN-activating ASOs at each region, two independent RNA quantification assays, and normalization by multiple housekeeping genes. Experiments on cells with the ASO-binding sites deleted indicate that the ASO-induced FXN activation was driven by indirect effects. RNA sequencing analyses showed that the two ASOs induced similar transcriptome-wide changes, which did not resemble the transcriptome of wild-type cells. This RNA-seq analysis did not identify directly base-paired off-target genes shared across ASOs. Mismatch studies identified two guanosine-rich motifs (CCGG and G4) within the ASOs that were required for FXN activation. The phosphorodiamidate morpholino oligomer analogs of our ASOs did not activate FXN, pointing to a PS-backbone-mediated effect. Our study demonstrates the importance of multiple, detailed control experiments and target validation in oligonucleotide studies employing novel mechanisms such as gene activation., (© The Author(s) 2022. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Objectives: KLHL6 is a recently described BTB-Kelch protein with selective expression in lymphoid tissues and is most strongly expressed in germinal center B cells., Methods: Using gene expression profiling as well as immunohistochemistry with an anti-KLHL6 monoclonal antibody, we have characterized the expression of this molecule in normal and neoplastic tissues. Protein expression was evaluated in 1,058 hematopoietic neoplasms., Results: Consistent with its discovery as a germinal center marker, KLHL6 was positive mainly in B-cell neoplasms of germinal center derivation, including 95% of follicular lymphomas (106/112). B-cell lymphomas of non-germinal center derivation were generally negative (0/33 chronic lymphocytic leukemias/small lymphocytic lymphomas, 3/49 marginal zone lymphomas, and 2/66 mantle cell lymphomas)., Conclusions: In addition to other germinal center markers, including BCL6, CD10, HGAL, and LMO2, KLHL6 immunohistochemistry may prove a useful adjunct in the diagnosis and future classification of B-cell lymphomas., (© American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com)

Degenerate splice site sequences mark the intron boundaries of pre-mRNA transcripts in multicellular eukaryotes. The essential pre-mRNA splicing factor U2AF(65) is faced with the paradoxical tasks of accurately targeting polypyrimidine (Py) tracts preceding 3' splice sites while adapting to both cytidine and uridine nucleotides with nearly equivalent frequencies. To understand how U2AF(65) recognizes degenerate Py tracts, we determined six crystal structures of human U2AF(65) bound to cytidine-containing Py tracts. As deoxy-ribose backbones were required for co-crystallization with these Py tracts, we also determined two baseline structures of U2AF(65) bound to the deoxy-uridine counterparts and compared the original, RNA-bound structure. Local structural changes suggest that the N-terminal RNA recognition motif 1 (RRM1) is more promiscuous for cytosine-containing Py tracts than the C-terminal RRM2. These structural differences between the RRMs were reinforced by the specificities of wild-type and site-directed mutant U2AF(65) for region-dependent cytosine- and uracil-containing RNA sites. Small-angle X-ray scattering analyses further demonstrated that Py tract variations select distinct inter-RRM spacings from a pre-existing ensemble of U2AF(65) conformations. Our results highlight both local and global conformational selection as a means for universal 3' splice site recognition by U2AF(65).

Background: Atypical genital naevi (AGN) are naevi of special sites with atypical histological features that overlap with those of malignant melanoma. Activating BRAF mutations, identified in the majority of banal melanocytic naevi and cutaneous melanomas, are reportedly uncommon in naevomelanocytic proliferations in nonsun-exposed sites. We have recently shown that constitutive activation of the BRAF-MEK-ERK signalling pathway in oncogenic BRAF-positive naevi increases expression and secretion of IGFBP7, which induces senescence and apoptosis., Objectives: To ascertain the frequency of BRAF V600E mutations in AGN compared with banal naevi without atypia. An additional aim was to assess the expression of IGFBP7 in oncogenic BRAF-positive AGN., Methods: Genomic DNA was isolated per protocol from seven genital naevi without atypia and 13 AGN for BRAF genotyping. Immunohistochemical staining for IGFBP7 was performed on all cases., Results: The BRAF V600E mutation was identified in 43% of genital naevi without atypia and 23% of AGN (P = 0.61). In both groups, IGFBP7 expression was maintained in 67% of BRAF V600E-positive cases., Conclusions: The prevalence of BRAF V600E in AGN suggests that ultraviolet exposure is not essential for generating the mutation. The BRAF V600E mutational status appears to be of limited diagnostic utility in distinguishing genital naevi that exhibit atypia from those that do not. Similar to oncogenic BRAF-positive common naevi without atypia, enhanced expression of the tumour suppressor IGFBP7 in oncogenic BRAF-positive AGN supports that they are biologically inert.

A well-recognized characteristic of the autoimmune disease, systemic lupus erythematosus (SLE), is the high level of activated T cells present in the blood. Because of the increased size and granularity of activated T cells, in flow cytometry one might expect to find increased numbers of cells falling outside a standard light-scatter lymphocyte gate, and indeed we now report that the percentage of T lymphocytes in the gate (% TiG) was below the normal range in 23 of 58 (40%) female patients because of increased scatter values. However, the surprising additional observation was made that 18 of 30 (60%) female first-degree relatives of the patients also fell below the normal % TiG range, suggesting the presence of T cell activation in these relatives. This view is strengthened by the strong inverse correlation between plasma total immunoglobulin G(IgG), which was raised in some relatives, and % TiG, as T cell activation is a requirement for IgG production. Conversely, there was no correlation with IgM, which has no comparable link with T cell activation. While a definitive interpretation must await the demonstration of activation antigen expression in relatives, these findings suggest the existence of a T cell activation trait, not harmful in itself, which, however, contributes to the development of disease in patients with SLE.

Monocyte-derived dendritic cells (MdDCs) from many patients with common variable immunodeficiency (CVID) have been shown recently to have reduced expression of surface molecules associated with maturity. Using flow cytometry and confocal microscopy, we now show that this is due to a partial failure to fix Class II DR molecules on the surface during procedures that induce full maturation in vitro in cells from normal subjects. Major histocompatibility complex (MHC) class I, CD86 and CD83 expression were expressed normally, but CD40 was reduced. These abnormalities are unlikely to be due to prior in vivo exposure of monocytes to lipopolysaccharide (LPS), as addition of LPS to monocytes from normal subjects in vitro caused a different pattern of changes. CVID MdDCs retained Class II DR in the cytoplasm during maturation, showed increased internalization of cross-linked Class II DR surface molecules and were unable to polarize DR within a lipid raft at contact sites with autologous lymphocytes. These cells retained some features of monocytes, such as the ability to phagocytose large numbers of fixed yeast and fluorescent carboxylated microspheres and expression of surface CD14. These abnormalities, if reflected in vivo, could compromise antigen presentation and may be a fundamental defect in the mechanism of the antibody deficiency in a substantial subset of CVID patients.

Background: Practicing oncologists are expected to easily assimilate large amounts of rapidly evolving clinical data. We hypothesized that U.S. oncologists rapidly familiarize themselves with new, practice-relevant, phase III clinical trial data. We tested this hypothesis in relation to the release of phase III data from the Eastern Cooperative Oncology Group 4599 trial on the role of bevacizumab in advanced non-small cell lung cancer (NSCLC)., Methods: We queried approximately 310 medical oncologists concerning their awareness of the bevacizumab data within 1 and 3 weeks after the data release or immediately after the 2005 Annual Meeting of the American Society of Clinical Oncology (ASCO)., Results: Prior to the ASCO meeting, 57% and 56% of the oncologists in the two research meetings, respectively, indicated "awareness" of the data release. Less than 25% selected an accurate descriptor of the released information from a short list of plausible options. After the ASCO meeting, the figures were 88% and 34%. Over 50% said they plan to use bevacizumab in NSCLC treatment as soon as reimbursement is secure. Eighty-two percent said they plan to use it in second- or third-line treatment; 56% said they plan to use it during second-line chemotherapy despite progression during first-line use. A large majority intend to use bevacizumab in dosages, tumor types, drug combinations, and/or patients not specifically supported by phase III data., Conclusion: Release of clinically relevant phase III data through electronic and print media is a poor vehicle for informing U.S. medical oncologists. For a commercially available agent, this can have important implications for potential use in untested and potentially unsafe clinical settings. Effective educational strategies for dealing with the new paradigm of "instant" release of clinical data need to be developed.

Natural killer (NK) cell cytotoxic activity and cell frequency, expressed as a percentage of total lymphocytes, have been determined in peripheral blood mononuclear cells from first-degree relatives of patients with systemic lupus erythematosus (SLE), the patients themselves, a group of rheumatoid arthritis (RA) patients and controls. Low levels of killing activity relative to controls were found in some members of all groups with the extent of depression falling into two ranges. Moderate reductions were seen in female (3/31, 10%) and male (4/14, 29%) relatives of SLE patients, female (12/60, 20%) and male (3/4, 75%) SLE patients and female RA patients (6/17, 35%). A more profound depression of killing activity was confined to other female SLE patients (15/60, 25%). There were strong correlations in all groups between killing activity and percentage of NK cells, but analysis of the ratio of these parameters and studies with purified preparations of NK cells suggest that the reduced activity in SLE frequently involves a defect in the killing capacity of the individual cells in addition to the reduced levels of NK cells. Azathioprine (AZA), which was used in treatment of 12 SLE patients, was invariably associated with low values of killing activity. It appears to substantially reduce the percentage of NK and B cells in an action unconnected with the NK cell abnormalities associated with SLE. The finding of low killing activity in relatives and a correlation between their activity and that of their patients support the view that NK cell deficiency is a genetic determinant of SLE. NK cells in SLE may produce insufficient levels of cytokines required for the regulation of IgG production.

The phenotype and function of monocyte derived dendritic cells (MdDC) were investigated in 25 patients with common variable immunodeficiency (CVID) to test for abnormalities that might help explain the failure of antibody production. Using MHC class II DR and CD86 as markers of maturation, DCs from the majority of CVID patients were normal. However 5 patients, the majority of whom had affected family members who had previously been shown to have a susceptibility genetic locus in the MHC region, expressed abnormally low levels of DR on repeated testing, in some cases associated with a reduced capacity to support antigen stimulated T cell proliferation; nevertheless costimulatory molecules for production of IL-13, IL-10 and IFN-gamma from T cells were intact. In contrast to DCs from healthy donors, DCs from many CVID patients had high spontaneous production of IL-8 and lipopolysaccharide stimulation often caused a reduction in DR expression. Expression of other cytokines (IL-1a, IL-6 and IL-12), either before or after LPS stimulation, was normal. The data suggests there is a fundamental defect in the maturation of MdDCs in a subset of CVID patients that may compromise antigen presentation and subsequent antibody production.

Background: Among patients diagnosed with advanced non-small-cell lung carcinoma (NSCLC), African-Americans have lower survival rates than non-African-Americans. Whether this difference is due to innate characteristics of the disease in the two ethnicities or to disparities in health care is not known. We investigated whether the disparity in survival would persist when patients were treated with similar systemic therapies (i.e., in phase II and phase III Cancer and Leukemia Group B [CALGB] trials)., Methods: We assessed 504 consecutive patients (458 non-African-American and 46 African-American) receiving systemic chemotherapy in CALGB studies for advanced NSCLC during the period from 1989 through 1998. Clinical and demographic characteristics, treatment received, and survival data were obtained from the CALGB database. Cox's proportional hazards model was used to assess the effect of race/ethnicity on survival after adjustment for other known prognostic factors. All statistical tests were two-sided., Results: The unadjusted 1-year survival rate was 22% (95% confidence interval [CI] = 13% to 38%) for African-American patients and 30% (95% CI = 26% to 35%) for non-African-American patients, a statistically significant difference (8%; 95% CI on the difference = 5% to 12%; P =.03). Multivariable adjustment for the effect of treatment arm, histology, and metastatic site at presentation did not alter the worse outcome for African-American patients. However, the effect of race/ethnicity disappeared after adjustment for performance status and weight loss. African-American patients were more likely than non-African-Americans to present with a poor performance status (83% versus 60%) and substantial weight loss (41% versus 27%) and to be unmarried (59% versus 28%), disabled (31% versus 15%), unemployed (17% versus 7%), and Medicaid recipients (30% versus 8%)., Conclusions: The relationship that we observed between poor performance, weight loss, and socioeconomic status suggests that social circumstances lead to African-Americans presenting with poorer prognostic features.

Tenascin C is a large extracellular matrix glycoprotein involved in morphogenesis and wound healing. The distribution and expression levels of tenascin were examined in photodamaged skin to investigate the hypothesis that photoaged skin displays characteristics of wound repair. In situ hybridization and semiquantitative immunohistochemistry were performed on paired skin biopsies from patients with varying levels of photodamage, using monoclonal antibodies and cRNA probes for tenascin and its large isoform. In sun-protected skin, tenascin protein was distributed adjacent to the dermoepidermal junction, usually sparsely and discontinuously; tenascin mRNA was detected in dermal fibroblasts and some keratinocytes. In photodamaged skin, tenascin protein was increased in proportion to the clinical level of photodamage (analysis of variance: P < 0.0001, n = 29). With increased photodamage, tenascin protein expression became continuous along the dermoepidermal junction, extending deeper into and sometimes throughout the papillary dermis; tenascin mRNA was detected throughout the epidermis. Large tenascin isoform protein and mRNA distribution mirrored that of pantenascin, suggesting that it may be the predominant species in photodamaged skin. There was no correlation between tenascin expression levels and age or sex, and no seasonal variation was noted. The results indicate that photodamaged skin demonstrates tenascin increases consistent with an early wound healing response. However, tenascin increases in photodamage appear to be permanent and may therefore interfere with effective repair of ultraviolet-induced damage. In conclusion, this study has shown that dermal tenascin expression increases in proportion to the degree of photodamage. In normal skin, the temporal and spatial patterns of tenascin expression during morphogenesis and tissue remodelling are crucial to their correct progression. In photoageing, the 'normal' control of tenascin expression seems to be abrogated.

Background: Both total dose and dose intensity of adjuvant chemotherapy are postulated to be important variables in the outcome for patients with operable breast cancer. The Cancer and Leukemia Group B study 8541 examined the effects of adjuvant treatment using conventional-range dose and dose intensity in female patients with stage II (axillary lymph node-positive) breast cancer., Methods: Within 6 weeks of surgery (radical mastectomy, modified radical mastectomy, or lumpectomy), 1550 patients with unilateral breast cancer were randomly assigned to one of three treatment arms: high-, moderate-, or low-dose intensity. The patients received cyclophosphamide, doxorubicin, and 5-fluorouracil on day 1 of each chemotherapy cycle, with 5-fluorouracil administration repeated on day 8. The high-dose arm had twice the dose intensity and twice the drug dose as the low-dose arm. The moderate-dose arm had two thirds the dose intensity as the high-dose arm but the same total drug dose. Disease-free survival and overall survival were primary end points of the study., Results: At a median follow-up of 9 years, disease-free survival and overall survival for patients on the moderate- and high-dose arms are superior to the corresponding survival measures for patients on the low-dose arm (two-sided P<.0001 and two-sided P = .004, respectively), with no difference in disease-free or overall survival between the moderate- and the high-dose arms. At 5 years, overall survival (average +/- standard error) is 79% +/- 2% for patients on the high-dose arm, 77% +/- 2% for the patients on the moderate-dose arm, and 72% +/- 2% for patients on the low-dose arm; disease-free survival is 66% +/- 2%, 61% +/- 2%, and 56% +/- 2%, respectively., Conclusion: Within the conventional dose range for this chemotherapy regimen, a higher dose is associated with better disease-free survival and overall survival.

As a first line of defence, the skin is equipped with a complex and interactive nerve fibre system to detect irritants and maintain homeostasis. The dermal component of this fibre network has been well characterized and fibres are known to extend throughout the viable epidermis as free nerve endings. To date, this epidermal component remains poorly characterized. We have visualized human volar forearm epidermal nerve fibres by laser-scanning confocal microscopy using the pan-neuronal marker, protein gene-product 9.5 and specific antibodies to substance P. calcitonin gene-related peptide and nerve growth factor. In addition to the varicose free nerve endings, there is a 3-D fibre network in normal human epidermis, with frequent branching of fibres. Branching can be seen to converge on a central trunk apparently extending to the dermis. Thin unmyelinated fibres can be seen in all layers of the viable epidermis. Substance P staining is rarely observed and is much less intense than the protein gene-product 9.5 staining. Calcitonin gene-related peptide and nerve growth factor were not detected in volar forearm epidermis by this method. Pretreatment of the skin in vivo with the neuropharmacological agent, capsaicin, resulted in loss of epidermal fibre staining indicating that these are sensory fibres of the primary C-afferent type. Epidermal innervation in racial and ethnic skin types was also assessed. No apparent difference in innervation was observed between European caucasian and Japanese/Chinese skin at the architectural or biochemical level, i.e. the presence, properties and biochemical content of fibres was similar in all cases tested.

Background: For many years, high dose radiation therapy was the standard treatment for patients with locally or regionally advanced non-small-cell lung cancer (NSCLC), despite a 5-year survival rate of only 3%-10% following such therapy. From May 1984 through May 1987, the Cancer and Leukemia Group B (CALGB) conducted a randomized trial that showed that induction chemotherapy before radiation therapy improved survival during the first 3 years of follow-up., Purpose: This report provides data for 7 years of follow-up of patients enrolled in the CALGB trial., Methods: The patient population consisted of individuals who had clinical or surgical stage III, histologically documented NSCLC; a CALGB performance status of 0-1; less than 5% loss of body weight in the 3 months preceding diagnosis; and radiographically visible disease. Patients were randomly assigned to receive either 1) cisplatin (100 mg/m2 body surface area intravenously on days 1 and 29) and vinblastine (5 mg/m2 body surface area intravenously weekly on days 1, 8, 15, 22, and 29) followed by radiation therapy with 6000 cGy given in 30 fractions beginning on day 50 (CT-RT group) or 2) radiation therapy with 6000 cGy alone beginning on day 1 (RT group) for a maximum duration of 6-7 weeks. Patients were evaluated for tumor regression if they had measurable or evaluable disease and were monitored for toxic effects, disease progression, and date of death., Results: There were 78 eligible patients randomly assigned to the CT-RT group and 77 randomly assigned to the RT group. Both groups were similar in terms of sex, age, histologic cell type, performance status, substage of disease, and whether staging had been clinical or surgical. All patients had measurable or evaluable disease at the time of random assignment to treatment groups. Both groups received a similar quantity and quality of radiation therapy. As previously reported, the rate of tumor response, as determined radiographically, was 56% for the CT-RT group and 43% for the RT group (P = .092). After more than 7 years of follow-up, the median survival remains greater for the CT-RT group (13.7 months) than for the RT group (9.6 months) (P = .012) as ascertained by the logrank test (two-sided). The percentages of patients surviving after years 1 through 7 were 54, 26, 24, 19, 17, 13, and 13 for the CT-RT group and 40, 13, 10, 7, 6, 6, and 6 for the RT group., Conclusions: Long-term follow-up confirms that patients with stage III NSCLC who receive 5 weeks of chemotherapy with cisplatin and vinblastine before radiation therapy have a 4.1-month increase in median survival. The use of sequential chemotherapy-radiotherapy increases the projected proportion of 5-year survivors by a factor of 2.8 compared with that of radiotherapy alone. However, inasmuch as 80%-85% of such patients still die within 5 years and because treatment failure occurs both in the irradiated field and at distant sites in patients receiving either sequential chemotherapy-radiotherapy or radiotherapy alone, the need for further improvements in both the local and systemic treatment of this disease persists.

Cyclic AMP response element binding protein (CREB) activates transcription of cAMP response element (CRE)-containing promoters following an elevation of intracellular cAMP. Here we show that CREB and the highly related protein ATF-1 are also potent transcription inhibitors. Strikingly, CREB inhibits transcription of multiple activators, whose DNA-binding domains and activation regions are unrelated to one another. Inhibition requires that the CREB dimerization and DNA-binding domains are intact. However, inhibition is not dependent upon the presence of a CRE in the promoter, and does not involve heterodimer formation between CREB and the activator. The ability of an activator protein to inhibit transcription in such a promiscuous fashion has not been previously reported.

Background: Chemotherapy may induce overall (complete plus partial) response rates of more than 50% and complete response rates up to 25% in extensive small-cell lung cancer (stage IIIB or IV), but survival is generally limited to 8-12 months. Interleukin-2 (IL-2) has demonstrated activity against this disease in vitro and has produced regression in melanoma and renal cell carcinoma., Purpose: The purpose of this study was to determine in a prospective, nonblinded, phase II trial the activity of IL-2 in patients with extensive small-cell lung cancer who had not achieved complete remission with chemotherapy., Methods: The 68 patients eligible for the study were initially treated with at least one dose of combination chemotherapy with cisplatin, doxorubicin, cyclophosphamide, and etoposide (PACE). Of the 50 who did not obtain complete remission with PACE, 24 who had measurable or evaluable disease and whose medical condition allowed further therapy were treated with IL-2. Beginning 3 weeks after the last dose of PACE, IL-2 was administered intravenously at 4.5 million Nutley units/m2 per day as a continuous infusion for 96 hours, followed by a 3-day rest. The planned duration of therapy was 8 weeks., Results: Of the 24 patients eligible to receive IL-2, four (17%) with measurable disease or evaluable but not measurable disease obtained a complete response after IL-2 therapy; one (4%) patient had a partial response. The overall response rate was 21%. Complete responses continued for 8, 9, and more than 11 months in three patients; the remaining patient developed acute myelomonocytic leukemia while in complete remission approximately 8 months after the start of IL-2 therapy. Only five of the 24 patients were able to complete the planned 8 weeks of IL-2 therapy. Therapy was discontinued in 11 patients because of life-threatening side effects, in six because of disease progression, and in two who withdrew from the study, probably related to IL-2 toxicity., Conclusions: These results indicate that IL-2 has some activity in extensive small-cell lung cancer and suggest that IL-2 is not cross-resistant with PACE therapy., Implications: Further studies are needed to define the optimum timing, dose, and schedule of IL-2 and to determine whether the agent has a role in the therapy of small-cell lung cancer.

Pelage hair follicles were isolated by gentle microdissection from 8-12-day-old rats, and maintained in supplemented Williams E medium. Length measurements made on freshly isolated hair follicles, and at 24-h intervals, showed a significant increase in hair follicle length over 48 h, after which time no further significant increase in length was observed. Photomicrographs of maintained follicles showed that this increase in hair follicle length could be attributed to the production of a keratinized hair shaft. Histology and [methyl-3H] thymidine autoradiography of freshly isolated hair follicles showed the dermal papilla to be elongated, with thymidine uptake located predominantly in the matrix cells of the hair follicle bulb adjacent to the dermal papilla. This pattern remained unaltered for the first 48 h of maintenance, but after 72 h the dermal papilla had rounded into a tight ball of cells, with very little thymidine uptake occurring in the adjacent matrix cells. On maintenance, fetal calf serum (FCS), epidermal growth factor (EGF) and 12-o-tetradecanoyl phorbol 13-acetate (TPA) all significantly stimulated [methyl-3H] thymidine and [U-14C] leucine uptake, but inhibited hair follicle elongation. Insulin-like growth factor-1 (IGF-1) had no significant effect on rates of hair follicle elongation and [methyl-3H] thymidine uptake, but significantly stimulated rates of [U-14C] leucine uptake. Transforming growth factor-beta 1 (TGF-beta 1) significantly inhibited both the rate of [methyl-3H] thymidine uptake and hair follicle elongation.

A simple and efficient method for synthesizing pure single stranded RNAs of virtually any structure is described. This in vitro transcription system is based on the unusually specific RNA synthesis by bacteriophage SP6 RNA polymerase which initiates transcription exclusively at an SP6 promoter. We have constructed convenient cloning vectors that contain an SP6 promoter immediately upstream from a polylinker sequence. Using these SP6 vectors, optimal conditions have been established for in vitro RNA synthesis. The advantages and uses of SP6 derived RNAs as probes for nucleic acid blot and solution hybridizations are demonstrated. We show that single stranded RNA probes of a high specific activity are easy to prepare and can significantly increase the sensitivity of nucleic acid hybridization methods. Furthermore, the SP6 transcription system can be used to prepare RNA substrates for studies on RNA processing (1,5,9) and translation (see accompanying paper).

Twenty-four lipsticks of various shades and colors were tested for mutagencitiy with the histidine-requiring tester strain Salmonella typhimurium TA98. Nine lipsticks were mutagenic without microsomal (S-9) activation. Dose-response effects were observed. Eight colorants listed as ingredients of the mutagenic lipsticsk were tested with and without S-9. Drug and Cosmetic (D&C) Orange No. 17, a monoazo dye with two nitro groups, was highly mutagenic in the absence of S-9. The mutagenic effect was decreased or lost in the presence of S-9 prepared from livers of male noninbred Sprague-Dawley rats given a single injection of Aroclor 1254. Eight lipsticsk matched for ingredients other than dyes were tested. Two containing D&C Orange No. 17 were directly mutagenic. The mutagenic effect was decreased by the presence of S-9. Only D&C Orange No. 17 was sufficiently mutagenic without microsomal activation to account for the mutagenicity observed in these lipsticks. Lipsticks containing D&C Orange No. 17 and those labeled with the words "may contain" D&C Orange No. 17 should be suspected of being mutagenic for S. typhimurium TA98. This dye and 2,4-dinitrosaniline, which may also be present, are potential health hazards. Assessment of their carcinogenicity awaits evaluation of results obtained by appropriate testing in animals.

Mammary explants from mice in midpregnancy cultured in a synthetic medium containing insulin and hydrocortisone respond to the addition of prolactin by the synthesis of milk proteins. The secretory response in alveolar lumina has served as a histologic endpoint in a sensitive bioassay for prolactin developed by Kleinberg and Frantz (J Clin Invest 50: 1557, 1971). This report demonstrates that the quantitative densitometric analysis of stained milk proteins (caseins) made in response to prolactin is a useful modification of that bioassay. Electrophoretic analysis of the proteins extracted from the explants permits a quantitative estimate of casein content. The amount of casein present after 5 days of incubation was found to be a measure of the prolactin concentration in the medium. No radioactive isotopes are used. The use of electrophoretic analysis has practical advantages over the histologic scoring used earlier, and has approximately the same range of sensitivity.

We recorded a bioassay for prolactin using densitometric analysis on polyacrylamide gels of caseins produced by mammary explants in vitro. A protein which also increased in the presence of increasing amounts of prolactin in the medium has now been identified. Its migration in several electrophoretic systems is the same as that of a whey protein of mouse milk, lactoferrin. It is an iron-binding glycoprotein with a molecular weight by SDS gel electrophoresis equal to mouse, human and bovine lactoferrin. It gives a precipitin reaction in an immunodiffusion system with monospecific antiserum raised in rabbits against mouse lactoferrin.

At concentrations of 7 times 10(-6) to 7 times 10(-5) M, derivatives consisting of the polycylic ring structures fluoranthene, fluorenone, fluorene, anthraquinone, xanthenone, and dibenzofuran with appropriate amine side chains inhibited by over 90% the purified RNA-directed DNA polymerase of avian myeloblastosis virus acting on poly(deoxyadenylate-deoxythymidylate) [poly(dA-dT)]. Of these, only the fluoranthene derivatives were strong inhibitors of the viral DNA polymerase directed by polyadenylate-oligodeoxythymidylate [poly(A)-(dT)12-18]. Low levels of fluoranthene derivatives (1 times 10(-5) M) also strongly inhibited polymerase with polyinosinate-oligodeoxycytidylate [poly(I)-(dC)12-18], activated calf thymus DNA, and viral 70S RNA as templates, but not with polycytidylate-oligodeoxyguanylate as template. A comparison of the activity of 11 fluoranthene derivatives with different side chains showed that the structure of the amine side chain influenced both the extent of antipolymerase activity with a given template and the relative inhibition with different synthetic DNA and RNA templates. The naturally occurring polyamines, spermine, spermidine, and putrescine, did not inhibit the activity of the viral DNA polymerase. Studies on the mechanism of action indicated that the synthetic derivatives inhibited polymerase activity by binding to the template and not to the enzyme: 1) inhibition by fluoranthene derivatives was overcome by the addition of excess template including poly(dA-dT), poly(A)-(dT)12-18, poly(I)-(dC)12-18, viral 70S RNA, and activated calf thymus DNA; 2) the degree of inhibition by fluoranthene derivatives was unaffected by the addition of the creased viral DNA polymerase; 3) with the same template, Escherichia coli DNA-directed RNA polymerase and the viral RNA-directed DNA polymerase were inhibited to about the same extent; and 4) the derivatives formed a complex with DNA, poly(I), and poly(A) that was stable to exclusion chromatography on Sephadex G-100. Several derivatives also had biologic activity, since they blocked the ability of the murine sarcoma virus to transform cells.