Chemotherapy-induced dynamic gene expression changes in vivo are prognostic in ovarian cancer.

BACKGROUND: The response of ovarian cancer patients to carboplatin and paclitaxel is variable, necessitating identification of biomarkers that can reliably predict drug sensitivity and resistance. In this study, we sought to identify dynamically controlled genes and pathways associated with drug response and its time dependence. METHODS: Gene expression was assessed for 14 days post-treatment with carboplatin or carboplatin-paclitaxel in xenografts from two ovarian cancer models: platinum-sensitive serous adenocarcinoma-derived OV1002 and a mixed clear cell/endometrioid carcinoma-derived HOX424 with reduced sensitivity to platinum. RESULTS: Tumour volume reduction was observed in both xenografts, but more dominantly in OV1002. Upregulated genes in OV1002 were involved in DNA repair, cell cycle and apoptosis, whereas downregulated genes were involved in oxygen-consuming metabolic processes and apoptosis control. Carboplatin-paclitaxel triggered a more comprehensive response than carboplatin only in both xenografts. In HOX424, apoptosis and cell cycle were upregulated, whereas Wnt signalling was inhibited. Genes downregulated after day 7 from both xenografts were predictive of overall survival. Overrepresented pathways were also predictive of outcome. CONCLUSIONS: Late expressed genes are prognostic in ovarian tumours in a dynamic manner. This longitudinal gene expression study further elucidates chemotherapy response in two models, stressing the importance of delayed biomarker detection and guiding optimal timing of biopsies.

Expression of steroid receptor coactivator 3 in ovarian epithelial cancer is a poor prognostic factor and a marker for platinum resistance.

BACKGROUND: Steroid receptor coactivator 3 (SRC3) is an important coactivator of a number of transcription factors and is associated with a poor outcome in numerous tumours. Steroid receptor coactivator 3 is amplified in 25% of epithelial ovarian cancers (EOCs) and its expression is higher in EOCs compared with non-malignant tissue. No data is currently available with regard to the expression of SRC-3 in EOC and its influence on outcome or the efficacy of treatment. METHODS: Immunohistochemistry was performed for SRC3, oestrogen receptor-α, HER2, PAX2 and PAR6, and protein expression was quantified using automated quantitative immunofluorescence (AQUA) in 471 EOCs treated between 1991 and 2006 with cytoreductive surgery followed by first-line treatment platinum-based therapy, with or without a taxane. RESULTS: Steroid receptor coactivator 3 expression was significantly associated with advanced stage and was an independent prognostic marker. High expression of SRC3 identified patients who have a significantly poorer survival with single-agent carboplatin chemotherapy, while with carboplatin/paclitaxel treatment such a difference was not seen. CONCLUSION: Steroid receptor coactivator 3 is a poor prognostic factor in EOCs and appears to identify a population of patients who would benefit from the addition of taxanes to their chemotherapy regimen, due to intrinsic resistance to platinum therapy.

Heterogeneity of persisting symptoms after sport-related concussion (SRC): exploring symptom subtypes and patient subgroups.

This study aimed to explore the heterogeneity of persisting symptoms after sport-related concussion (SRC). We examined the structure of symptom subtypes within 163 patients with SRC (M = 16.7 weeks post-injury). Subsequently, we investigated the existence of subgroups of patients based on comparable configuration of co-occurring symptom subtypes. To explore factors that may contribute to the emergence of SRC patient subgroups, subgroups were compared on pre-injury (i.e., demographics and medical history), personality (Severity Indices of Personality Problems Short Form) and SRC characteristics (i.e., history of prior concussions, loss of consciousness and post-traumatic amnesia). To investigate the relevance of SRC subgrouping for clinical outcome, subgroups were compared on symptom severity (Sport Concussion Assessment Tool 5). The results provide empirical evidence for the existence of symptom subtypes, characterized as a: neurocognitive, fatigue, emotional, migraine and vestibular-ocular symptom subtype in patients with persisting SRC. Study results also showed evidence for the existence of SRC subgroups of patients with a comparable configuration of co-occurring prevailing symptom subtypes, including a neurocognitive-migraine, fatigue, migraine-emotional and neurocognitive-emotional subgroup. The subgroups differed on pre-injury, personality and SRC characteristics, suggesting that these factors may contribute to the emergence of specific SRC patient subgroups. The subgroups also differed in the severity of persisting symptoms, highlighting the clinical relevance of SRC subgrouping. These results support the idea that patient subgroups with persisting SRC with a comparable pattern of co-occurring symptom subtypes exists, which may require targeted prognosis, clinical management and treatment to optimize recovery.

SARS-CoV-2 Antibody Profiles in Maternal Serum and Breast Milk Following mRNA COVID-19 Vaccination: A Longitudinal Prospective Observational Cohort Study.

COVID-19 vaccination during pregnancy protects infants against symptomatic COVID-19. Vaccination of lactating mothers may offer additional protection, but our understanding of immune responses in breast milk is limited. We, therefore, performed a single-center prospective cohort study of lactating mothers who received a COVID-19 mRNA primary vaccine series to evaluate the durability, breadth, and neutralizing capacity of the antibody responses in breast milk. Spike IgG- and IgA-binding antibodies of ancestral SARS-CoV-2 in serum and breast milk were quantified over 9 months using Meso Scale Discovery (MSD) V-PLEX assays, and ancestral titers were compared to four variants of concern (Alpha, Beta, Delta, Gamma) at a single time point. Neutralizing antibodies against ancestral SARS-CoV-2 and Omicron BA.4/5 were compared before and after vaccination using a pseudovirus-neutralization assay. Eleven lactating mothers received either Pfizer BNT162b2 (7/11) or Moderna mRNA-1273 (4/11) vaccine primary series. IgG and IgA titers increased in serum and breast milk following each dose, peaking 1-4 weeks after series completion. Titers remained significantly elevated for 7-9 months, except for in breast milk IgA which returned to baseline within 1 month. Furthermore, binding antibodies against all included variants were detected in breast milk collected 1-3 weeks after series completion. However, while vaccination induced a strong neutralizing response against ancestral SARS-CoV-2 in serum and more modest response in breast milk, it did not induce neutralizing antibodies against Omicron BA.4/5 in either specimen type. This study demonstrates that maternal COVID-19 mRNA vaccination may enhance immune protection for infants through breast milk via increased IgG- and IgA-binding-and-neutralizing antibodies; although, variant-specific boosters may be required to optimize immune protection.

Defining the molecular response to trastuzumab, pertuzumab and combination therapy in ovarian cancer.

BACKGROUND: Trastuzumab and pertuzumab target the Human Epidermal growth factor Receptor 2 (HER2). Combination therapy has been shown to provide enhanced antitumour activity; however, the downstream signalling to explain how these drugs mediate their response is not clearly understood. METHODS: Transcriptome profiling was performed after 4 days of trastuzumab, pertuzumab and combination treatment in human ovarian cancer in vivo. Signalling pathways identified were validated and investigated in primary ovarian xenografts at the protein level and across a timeseries. RESULTS: A greater number and variety of genes were differentially expressed by the combination of antibody therapies compared with either treatment alone. Protein levels of cyclin-dependent kinase inhibitors p21 and p27 were increased in response to both agents and further by the combination; pERK signalling was inhibited by all treatments; but only pertuzumab inhibited pAkt signalling. The expression of proliferation, apoptosis, cell division and cell-cycle markers was distinct in a panel of primary ovarian cancer xenografts, suggesting the heterogeneity of response in ovarian cancer and a need to establish predictive biomarkers. CONCLUSION: This first comprehensive study of the molecular response to trastuzumab, pertuzumab and combined therapy in vivo highlights both common and distinct downstream effects to agents used alone or in combination, suggesting that complementary pathways may be involved.

A gene on the HER2 amplicon, C35, is an oncogene in breast cancer whose actions are prevented by inhibition of Syk.

BACKGROUND: C35 is a 12 kDa membrane-anchored protein endogenously over-expressed in many invasive breast cancers. C35 (C17orf37) is located on the HER2 amplicon, between HER2 and GRB7. The function of over-expressed C35 in invasive breast cancer is unknown. METHODS: Tissue microarrays containing 122 primary human breast cancer specimens were used to examine the association of C35 with HER2 expression. Cell lines over-expressing C35 were generated and tested for evidence of cell transformation in vitro. RESULTS: In primary breast cancers high levels of C35 mRNA expression were associated with HER2 gene amplification. High levels of C35 protein expression were associated with hallmarks of transformation, such as, colony growth in soft agar, invasion into collagen matrix and formation of large acinar structures in three-dimensional (3D) cell cultures. The transformed phenotype was also associated with characteristics of epithelial to mesenchymal transition, such as adoption of spindle cell morphology and down-regulation of epithelial markers, such as E-cadherin and keratin-8. Furthermore, C35-induced transformation in 3D cell cultures was dependent on Syk kinase, a downstream mediator of signalling from the immunoreceptor tyrosine-based activation motif, which is present in C35. CONCLUSION: C35 functions as an oncogene in breast cancer cell lines. Drug targeting of C35 or Syk kinase might be helpful in treating a subset of patients with HER2-amplified breast cancers.

Quantitative analysis of changes in ER, PR and HER2 expression in primary breast cancer and paired nodal metastases.

BACKGROUND: Assessment of receptors [estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2)] is routinely carried out on primary tumour in order to select appropriate adjuvant therapy; the same analysis is not carried out on nodal metastases. Since de novo resistance to therapy is common, we quantified differences in receptor expression between primary and nodal disease in order to assess whether this might contribute to therapeutic resistance. PATIENTS AND METHODS: A total of 385 patients with invasive primary breast carcinomas and paired lymph nodes (n = 211) were assessed for ER, PR and HER2 expression using quantitative immunofluorescence. Cut-points were defined by comparison with tumours scored by immunohistochemistry (IHC) and FISH. Differences in expression for each of the markers and molecular phenotype were analysed. RESULTS: Quantitative receptor expression shows a wide dynamic range compared with IHC. Overall, 46.9% cases had disparate breast/node receptor status of at least one receptor. Many of the differences in expression between primary tumour and node are large magnitude (greater than fivefold) changes. Triple-negative phenotype changes in 23.1% of cases. CONCLUSIONS: A significant number of patients show discordant quantitative expression of molecular markers between primary and nodal disease. Appropriately measured, lymph node receptor status could be a more accurate measurement for guiding adjuvant therapy, which requires testing in a clinical trial.

Subtypes of Sport-Related Concussion: a Systematic Review and Meta-cluster Analysis.

OBJECTIVE: Current clinical guidelines provide a unitary approach to manage sport-related concussion (SRC), while heterogeneity in the presentation of symptoms suggests that subtypes of SRC may exist. We systematically reviewed the available evidence on SRC subtypes and associated clinical outcomes. DATA SOURCES: Ovid Medline, Embase, PsycINFO, and SPORTDiscus ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Electronic databases were searched for studies: (i) identifying SRC symptom clusters using classification methodology; or (ii) associating symptom clusters to clinical outcome variables. A total of 6,146 unique studies were identified, of which 75 full texts were independently assessed by two authors for eligibility. A total of 22 articles were included for systematic review. DATA EXTRACTION: Two independent authors performed data extraction and risk of bias analysis using the Cochrane Collaboration tool. DATA SYNTHESIS: Six studies found evidence for existence of SRC symptom clusters. Combining the available literature through Multiple Correspondence Analysis (MCA) provided evidence for the existence of a migraine cluster, a cognitive-emotional cluster, a sleep-emotional cluster, a neurological cluster, and an undefined feelings cluster. Nineteen studies found meaningful associations between SRC symptom clusters and clinical outcomes. Clusters mapping to the migraine cluster were most frequently reported in the literature and were most strongly related to aspects of clinical outcome. CONCLUSIONS: The available literature provides evidence for the existence of at least five subtypes in SRC symptomatology, with clear relevance to clinical outcome. Systematically embedding the differentiation of SRC subtypes into prognosis, clinical management, and intervention strategies may optimize the recovery from SRC.

Implantable biosensors and their contribution to the future of precision medicine.

Precision medicine can be defined as the prevention, investigation and treatment of diseases taking individual variability into account. There are multiple ways in which the field of precision medicine may be advanced; however, recent innovations in the fields of electronics and microfabrication techniques have led to an increased interest in the use of implantable biosensors in precision medicine. Implantable biosensors are an important class of biosensors because of their ability to provide continuous data on the levels of a target analyte; this enables trends and changes in analyte levels over time to be monitored without any need for intervention from either the patient or clinician. As such, implantable biosensors have great potential in the diagnosis, monitoring, management and treatment of a variety of disease conditions. In this review, we describe precision medicine and the role implantable biosensors may have in this field, along with challenges in their clinical implementation due to the host immune responses they elicit within the body.

Interaction between transcriptional activator protein LAC9 and negative regulatory protein GAL80.

In Saccharomyces cerevisiae, transcriptional activation mediated by the GAL4 regulatory protein is repressed in the absence of galactose by the binding of the GAL80 protein, an interaction that requires the carboxy-terminal 28 amino acids of GAL4. The homolog of GAL4 from Kluyveromyces lactis, LAC9, activates transcription in S. cerevisiae and is highly similar to GAL4 in its carboxyl terminus but is not repressed by wild-type levels of GAL80 protein. Here we show that GAL80 does repress LAC9-activated transcription in S. cerevisiae if overproduced. We sought to determine the molecular basis for the difference in the responses of the LAC9 and GAL4 proteins to GAL80. Our results indicate that this difference is due primarily to the fact that under wild-type conditions, the level of LAC9 protein in S. cerevisiae is much higher than that of GAL4, which suggests that LAC9 escapes GAL80-mediated repression by titration of GAL80 protein in vivo. The difference in response to GAL80 is not due to amino acid sequence differences between the LAC9 and GAL4 carboxyl termini. We discuss the implications of these results for the mechanism of galactose metabolism regulation in S. cerevisiae and K. lactis.

Correlation between the molecular weight and potency of polar compounds which induce the differentiation of HL-60 human promyelocytic leukemia cells.

Structure-activity studies of a series of polar organic compounds, including N,N-dimethylformamide, N-methylformamide, and related ureas and acetamides, were performed with regard to their ability to promote the terminal differentiation of the human promyelocytic leukemia cell line HL-60 to granulocyte-like cells. Functional and morphological criteria were used to assess the percentage of differentiated cells which arose from their continuous incubation with different concentrations of each agent over a period of 96 h. All of the alkylformamides, alkylacetamides, and alkylureas tested were found to induce differentiation, regardless of structure. Inspection of the results showed that there was a linear relationship (r = -0.937) between the molecular weight of each compound and the logarithm of the concentration which was required to bring about the differentiation of the greatest number of cells, while viability was generally maintained at greater than 85%. Once established, this relationship was used to predict the potency of several polar solvents which were structurally unrelated to the formamides. For example, methanol, ethanol, and acetone were all inducers of differentiation with a potency predictable from their molecular weight alone. The terminal differentiation induced by all of the compounds was only accomplished by cells which were capable of replication prior to differentiation. At concentrations which prevented a single replication and brought about a fall in cell viability over 96 h, no differentiation was observed. A correlation was observed between the molecular weight of each compound and the logarithm of its concentration to bring about cytotoxicity without differentiation (r = -0.935), and the line was almost parallel to that defining the concentration required for optimal differentiation (slope values of -0.02126 and -0.02288). A poorer (r = -0.6654) correlation was found between the logarithm of the octanol-water partition coefficient and the logarithm of the concentration required for optimal differentiation, when the data for 12 of the polar organic compounds were analyzed. The results suggest that no special structural requirements are necessary for the alkylformamides, -acetamides, -ureas, and related compounds to induce the terminal differentiation of HL-60 cells to granulocyte-like cells, but that the activity of each compound could be predicted from their molecular weight. The concentrations required to induce differentiation were marginally lower than those which were cytostatic or cytotoxic, which suggested that a toxic threat to the cells was sufficient to induce differentiation.(ABSTRACT TRUNCATED AT 400 WORDS)

Growth of small cell lung cancer cells: stimulation by multiple neuropeptides and inhibition by broad spectrum antagonists in vitro and in vivo.

Neuropeptides are increasingly implicated in the control of cell proliferation and their mechanisms of action are attracting intense interest. The early complex cascade of events initiated by peptides of the bombesin family including gastrin-releasing peptide is increasingly understood. The cause-effect relationships and temporal organization of these early signals and molecular events provide a paradigm for the study of other growth factors and mitogenic neuropeptides and illustrate the activation and interaction of a variety of signaling pathways. These peptides may also act as autocrine growth factors for certain small cell lung cancer cells. The results discussed here strongly suggest that the autocrine growth loop of bombesin-like peptides may be only a part of an extensive network of autocrine and paracrine interactions involving a variety of Ca(2+)-mobilizing neuropeptides in small cell lung cancer including bradykinin, cholecystokinin, galanin, neurotensin, and vasopressin. In this context, broad spectrum antagonists that prevent the function of multiple Ca(2+)-mobilizing receptors are of special interest. These antagonists block neuropeptide mediated signals and inhibit small cell lung cancer growth in vitro and in vivo. Thus, broad spectrum neuropeptide antagonists constitute potential anticancer agents.

Broad spectrum neuropeptide antagonists inhibit the growth of small cell lung cancer in vivo.

The proliferation of small cell lung cancer (SCLC) cells appears sustained by multiple autocrine and paracrine circuits involving Ca2+ mobilizing neuropeptides. Consequently, broad spectrum neuropeptide antagonists which inhibit SCLC growth in vitro have been suggested as potential anticancer agents. Here we evaluated this hypothesis using xenografts of WX322 cells, a SCLC cell line that responds to multiple Ca2+ mobilizing neuropeptides. The broad spectrum neuropeptide antagonists [Arg6,D-Trp7,9,MePhe8]substance P(6-11) and [D-Arg1,D-Phe5,Trp7,9Leu11[substance P were shown to inhibit the growth of WX322 xenografts in nude mice. Similar results were obtained with xenografts of the SCLC cell line H69. The results indicate that broad spectrum neuropeptide antagonists can inhibit the growth of SCLC in vivo and suggest that these antagonists could be useful in the treatment of SCLC.

Characterization of the aryl hydrocarbon receptor and aryl hydrocarbon responsiveness in human ovarian carcinoma cell lines.

The human ovarian carcinoma cell lines PE01, PE04, and PE06 express the estrogen receptor and studies with the PE04 cells have shown that tamoxifen inhibits 17 beta-estradiol-induced proliferation. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a broad spectrum antiestrogen which works through the aryl hydrocarbon receptor. Incubation of the three cell lines with [3H]TCDD followed by isolation of nuclear extracts showed that the PE01, PE04, and PE06 cells express the aryl hydrocarbon receptor (23 to 87 fmol/mg protein) which exhibits sedimentation properties (7.5 to 7.9 S) on sucrose gradients similar to that observed in other mammalian species. Aryl hydrocarbon responsiveness was determined by the induction of P4501A1 mRNA levels and ethoxyresorufin O-deethylase activity by TCDD. Induction of both parameters was observed only in the PE04 cells. Gel mobility shift assays with a consensus dioxin-responsive element (DRE, 26-mer) showed that after incubation of the nuclear extracts from the 3 cell lines with 32P-DRE a retarded band formed only with nuclear receptor complex from PE04 cells. 17 beta-Estradiol stimulated proliferation of the PE04 and PE06 but not the PE01 cells; 1 nM TCDD alone either did not affect or inhibited the growth of these cells and 1 nM TCDD significantly inhibited the 17 beta-estradiol-induced proliferation of the PE04 and PE06 cells. Treatment of the PE04 cells with 1 nM 17 beta-estradiol resulted in a time-dependent enhanced secretion of the M(r) 52,000 protein (procathepsin D) and, after 48 h, a 51% increase in the secretion of this protein was observed. Cotreatment of the PE04 cells with 0.1 or 1.0 nM TCDD completely inhibited the 17 beta-estradiol-induced secretion of the M(r) 52,000 protein. These data show that TCDD exhibits antiestrogenic activity in estrogen receptor-positive ovarian carcinoma cell lines; however, in the PE06 cells, there was no correlation between the effects of TCDD on the induction of CYP1A1 gene expression and the results of the gel shift assay (i.e., nonresponsiveness) versus the observed antiestrogenic activity.

Expression of erbB-4/HER-4 growth factor receptor isoforms in ovarian cancer.

Immunohistochemical expression of erbB4 protein was identified in 93% (49 of 53) of ovarian cancers using the HFR-1 antibody (targeted to the cytoplasmic domain of the erbB4 receptor) and in 89% (47 of 53) of ovarian cancers using the H4.77.16 antibody (targeted to the extracellular domain). Tumors of serous histology were more likely to express a higher level of erbB4 than endometrioid tumors, and for stage III serous tumors, long-term survival was associated with moderate to high coexpression of erbB4 and erbB2. Within ovarian cancer cell lines, high erbB4 expression was associated with cisplatin resistance. Using reverse transcription-PCR, the presence of multiple isoforms of erbB4 mRNA was identified in both ovarian primary tumors and cell lines. Splice variants in the juxtamembrane (JM-a and JM-d) and cytoplasmic (CT-a and CT-b) regions were identified in mRNA of both cell lines and primary tumors. The use of an anti-erbB4 blocking antibody suggested that erbB4 was not the mediator of the growth stimulatory effects of neuregulin in ovarian cancer cells and indeed could potentially antagonize this effect.

Antitumor activity and pharmacokinetics in mice of 8-carbamoyl-3-methyl-imidazo[5,1-d]-1,2,3,5-tetrazin-4(3H)-one (CCRG 81045; M & B 39831), a novel drug with potential as an alternative to dacarbazine.

A number of 3-alkyl analogues of the experimental antitumor drug mitozolomide [8-carbamoyl-3-(2-chloroethyl)imidazo[5,1-d]-1,2,3,5-tetrazin-4(3H )-one] have been screened against murine tumors in vivo. Only the compounds with a 3-methyl- or 3-bromoethyl group possessed significant antitumor activity against the TLX5 lymphoma. The 3-methyl analogue, 8-carbamoyl-3-methylimidazo[5,1-d]-1,2,3,5-tetrazin-4(3H)-one (CCRG 81045), was investigated further and found to possess good activity, when administered i.p., against the L1210 and P388 leukemias, the M5076 reticulum cell sarcoma, B16 melanoma, and ADJ/PC6A plasmacytoma. The drug was also active when administered p.o. to mice bearing the L1210 leukemia. A daily for 5 days schedule of 100 mg/kg CCRG 81045 produced increases of survival time of treated animals compared to controls of 176 and greater than 235% against the P388 and L1210 leukemias, respectively. In the female C57BL x DBA/2 F1 mouse the 10% lethal dose was 125 mg/kg daily for 5 days. CCRG 81045 was found to undergo mild alkaline hydrolysis and ring fission to form the linear triazene 5-(3-methyltriazen-1-yl)imidazole-4-carboxamide, which is the putative metabolite formed upon metabolic activation of the antitumor drug dacarbazine [5-(3,3-dimethyltriazen-1-yl)imidazole-4-carboxamide]. The half-life of CCRG 81045 at 37 degrees C in 0.2 M phosphate buffer (pH 7.4) was 1.24 h, whereas that of 5-(3-methyltriazen-1-yl)imidazole-4-carboxamide at 25 degrees C was reported to be 8 min (F. H. Shealy and C. A. Krauth, J. Med. Chem., 9:34-37, 1966). The half-life of CCRG 81045 in human plasma in vitro at 37 degrees C was 0.42 h. Pharmacokinetic experiments conducted in BALB/c mice produced plasma profiles of CCRG 81045, administered i.p. or p.o., which showed a rapid absorption phase, elimination half-lives of 1.13 h (i.p.) and 1.29 h (p.o.), and a bioavailability of 0.98.

Effect of sodium butyrate and other differentiation inducers on poorly differentiated human ovarian adenocarcinoma cell lines.

We have studied the effects of sodium butyrate, retinoic acid, and dimethyl sulfoxide on two human ovarian carcinoma cell lines PE04 and PE01. PE04 cells, after treatment with sodium butyrate at cytostatic doses (2-3 mM for 4 days), exhibited phenotypic changes including induction of alkaline phosphatase and determinants recognized by the monoclonal antibodies 123C3 and 123A8. These effects are not simply the result of cytostasis as they were not produced by dimethyl sulfoxide or retinoic acid. Other markers are also modified by sodium butyrate including lipid, acid mucin, and glycogen. Retinoic acid modulated expression of lipid and CA125, while dimethyl sulfoxide reduced expression of CA125. Other short chain fatty acids such as propionic acid and valeric acid (in addition to butyric acid) also induced alkaline phosphatase and the determinants recognized by 123C3 and 123A8 in PE04 cells. Other differentiation inducers and cytotoxic agents studied did not induce these markers at cytostatic concentrations. The effects of sodium butyrate (and related short chain fatty acids) thus appear to be relatively specific for this cell line.

Phase II preclinical drug screening in human tumor xenografts: a first European multicenter collaborative study.

In a European joint project carried out in 6 laboratories a disease-oriented program was set up consisting of a panel of 7 tumor types, each represented by 4 to 8 different human tumor lines, for secondary screening of promising anticancer drugs. Human tumor lines were selected on the basis of differences in histology, growth rate, and sensitivity to conventional cytostatic agents. Xenografts were grown s.c. in nude mice, and treatment was started when tumors reached a mean diameter of 6 mm in groups of mice where at least 6 tumors were evaluable. Drugs were given at the maximum tolerated dose. For evaluation of drug efficacy, median tumor growth curves were drawn, and specific growth delay and treated/control x 100% were calculated. Doxorubicin (8 mg/kg i.v. days 1 and 8) was effective (treated/control < 50%, and specific growth delay > 1.0) in 0 of 2 breast cancers, 1 of 3 colorectal cancers, 2 of 5 head and neck cancers, 3 of 6 non-small cell lung cancers, 4 of 6 small cell lung cancers, 0 of 3 melanomas, and 3 of 6 ovarian cancer lines. Amsacrine (8 mg/kg i.v. days 1 and 8) was not effective, while datelliptium (35 mg/kg i.p. days 1 and 8) was active against 2 of 6 small cell lung cancer lines. Brequinar sodium (50 mg/kg i.p. days 1-5) showed efficacy in 4 of 5 head and neck cancers, 5 of 8 non-small cell lung cancers, and 4 of 5 small cell lung cancer lines. The project has been shown to be a feasible approach. Clinical activity for doxorubicin and inactivity for amsacrine against solid tumor types was confirmed in the human tumor xenograft panel. Additional anticancer drugs will be studied in the European joint project to further define the reliability of this novel, promising screening approach.

Experimental antitumor activity against murine tumor model systems of 8-carbamoyl-3-(2-chloroethyl)imidazo[5,1-d]-1,2,3,5-tetrazin-4(3 H)-one (mitozolomide), a novel broad-spectrum agent.

8-Carbamoyl-3-(2-chloroethyl)imidazo[5,1-d]-1,2,3,5-tetrazin-4(3H) -one (mitozolomide) demonstrates curative action against a range of murine tumor model systems. At single doses of between 20 and 40 mg/kg, the latter of which approximates the 10% lethal dose value in mice, the compound elicited cures against the L1210 and P388 leukemias irrespective of the route of tumor and/or drug administration; in these tests, animals receiving 10(5) cells i.p. survived greater than 60 days after treatment. Potent effects were also observed against the TLX5 lymphoma (s.c.) and B16 melanoma (i.p.). In other experiments, 7 of 10 animals implanted with 2 X 10(5) Lewis lung carcinoma cells survived greater than 60 days while 10 of 10 animals survived greater than 60 days after implantation of the Colon 26 tumor. Potent inhibition of the solid tumor models was also observed with complete cures of the Colon 38, M5076 sarcoma, and ADJ/PC6A plasmacytoma. In cross-resistance studies, the compound was ineffective against an L1210 leukemia made resistant to 1,3-bis(2-chloroethyl)-1-nitrosourea and against a TLX5 lymphoma resistant to dimethyltriazenes but cured animals bearing the L1210 leukemia with derived resistance to cyclophosphamide.

Characterization and properties of nine human ovarian adenocarcinoma cell lines.

Four series of cell lines have been derived from patients with ovarian adenocarcinoma. Nine cell lines have been established at one from a solid metastasis. Six lines were derived from the ascites or pleural effusion of patients with poorly differentiated adenocarcinoma: PEO1, PEO4, and PEO6 from one patient, PEA1 and PEA2 from a second, and PEO16 from a third. Three lines (PEO14 and PEO23 from ascites and TO14 from a solid metastasis) were derived from a patient with a well-differentiated serous adenocarcinoma. Each set of cell lines was morphologically distinct. The five cell lines PEO1, PEO4, PEO6, PEA1, and PEA2 had cloning efficiencies on plastic of 1-2% and only a few cells in these lines expressed alkaline phosphatase or vimentin. Only a low percentage of these cells reacted with the monoclonal antibodies 123C3 and 123A8 but most reacted with OC125. Conversely the cell lines PEO14, TO14, PEO23, and PEO16 were characterized by low cloning efficiency values (less than 0.05%), marked expression of alkaline phosphatase and vimentin, and good reaction with 123C3 and 123A8 but not OC125. These four cell lines also exhibited dome formation. Four of the cell lines, PEO1, PEO4, PEO6, and PEO16, have been xenografted into immune-deprived mice and found to be tumorigenic.