CTNI-50. A RANDOMIZED PHASE 2 TRIAL OF CEDIRANIB/OLAPARIB VERSUS BEVACIZUMAB IN PATIENTS WITH RECURRENT GLIOBLASTOMA: UPDATED RESULTS

PURPOSE

Hypoxia from inhibition of angiogenesis reduces DNA repair capacity. Targeting homologous recombination pathway also has anti-angiogenic effects. To examine the synergistic effects of disrupting DNA repair pathways and angiogenesis in glioblastoma, we combine cediranib (ced), a pan vascular endothelial growth factor (VEGF) receptor inhibitor with olaparib (ola), a poly-ADP ribose polymerase (PARP) inhibitor compared with bevacizumab (bev), a VEGF-A inhibitor alone. To identify potential biomarkers predicting response to treatments, we also perform whole exome sequencing on archival tissues.

METHODS

Bevacizumab-naïve adult patients with first or second recurrence of glioblastoma after radiation and temozolomide were randomly assigned to cediranib (30mg PO daily)/olaparib (200mg PO twice daily) or bevacizumab (10mg/kg IV every 2 weeks). The primary end point was progression-free survival (PFS) at 6 months. The secondary end points included safety and overall survival (OS). Whole exome sequencing of formalin-fixed paraffin embedded archival tissue from 23 patients was performed.

RESULTS

We are presenting the final data from this trial. Between December 2017 and November 2018, a total 70 adult patients with recurrent glioblastoma were randomly assigned to receive ced/ola (n = 35) or bev (n = 35). With a data cut off on 5/30/2022, median PFS was 118 days and 92 days in ced/ola and bev groups, respectively (hazard ratio, 1.099, 95% CI 0.6-2, p = 0.76). Median overall survival was 269.5 days and 192 days in ced/ola and bev groups, respectively (hazard ratio, 0.6892, 95% CI 0.39-1.2, p = 0.2). Whole exome sequencing was performed in total 23 patients (24 samples), 14 patients in the ced/ola group and 9 patients in the bev group.

CONCLUSION

No significant survival benefit was observed in patients with recurrent glioblastoma treated with ced/ola compared to patients treated with bev monotherapy. Potential biomarkers predicting response to treatment identified from the whole exome sequencing on archival tissues will be presented.

INNV-40. REAL WORLD INTEGRATION OF THE NEUROLOGIC ASSESSMENT IN NEURO-ONCOLOGY (NANO) SCALE IN CLINICAL PRACTICE IN PATIENTS WITH IDH-WT GBM

BACKGROUND

The neurologic assessment in neuro-oncology (NANO) scale was developed as a standardized metric to objectively measure neurologic function in patients with brain tumors and complement radiographic assessment in defining overall outcome. The scale has been incorporated in clinical trials. Early data is suggestive of feasibility and that NANO contributes to overall outcome assessment. However, real-world use of the NANO scale to drive clinical-decision making and the predictive value of the NANO scale to determine overall survival remains unclear in IDH-wt GBM.

METHODS

We report on an ongoing study using the NANO scale to evaluate neurologic function in patients with IDH-wt GBM, seen at Dana-Farber Cancer Institute (DFCI). Patient demographics, tumor histology and molecular status, treatment history and progression dates are being captured. NANO score, as collected by a built-in scale in our institutional electronic medical record (EMR), functional status (Karnofsky performance status) and corticosteroid dose are collected at prespecified time points (prior to start of therapy, and during each subsequent MRI visit). Changes in the NANO score will be correlated to overall survival. Statistical analyses including descriptive data analysis and generalized linear models will be performed using R (version 3.4.3).

RESULTS

Since June 2020, 50 patients have been enrolled in this study, including 42 (84%) with ≥2 follow up visits. Study accrual was initially impacted by the COVID-19 pandemic, but adaptation to a virtual platform for NANO allowed for improved recruitment and follow up of patients. Study results will be available for discussion at the 2021 SNO conference.

CONCLUSIONS

Evaluation of neurologic function by NANO is feasible in a virtual framework in a prospective study in patients with GBM, aided by integration of the scale in our institutional EMR. NANO is able to objectively track neurologic function throughout disease course in IDH-wt GBM.

Abstract 2953: Rev-erbα modulates Myc-driven cancer cell growth and altered metabolism

Circadian rhythms are regulated by feedback loops comprising a network of factors that regulate Clock-associated genes. Chronotherapy seeks to take advantage of altered circadian rhythms in some cancers to better time administration of treatments to increase efficacy and reduce toxicity. While many cancers have perturbed expression of core circadian rhythm genes, the molecular basis underlying these perturbations and their functional implications in oncogenesis are still poorly understood, and so it is impossible to predict which cancers have altered circadian rhythms and would best benefit from chronotherapy. We have observed in cancer cell models of osteosarcoma, hepatocellular carcinoma, and neuroblastoma that the c-Myc and N-Myc oncogenic transcription factors disrupt oscillation of the circadian clock by specifically upregulating the circadian rhythm gene and nuclear hormone receptor NR1D1 (Rev-erbα). Interestingly, while Rev-erbα has not been previously recognized as an oncogene, data from The Cancer Genome Atlas revealed that it is amplified in many forms of human cancer, and we also observed that Rev-erbα was upregulated in primary human neuroblastoma and associated with poor prognosis. Therefore, we hypothesized that Rev-erbα is a novel oncogene downstream of Myc and is important for cancer cell growth.

Here we show that Rev-erbα is specifically essential for the growth of Myc-driven hepatocellular carcinoma cells, as the related protein Rev-erbβ did not strongly influence growth. While knockdown of Rev-erbα expression by siRNA slowed growth, it did not cause cell death or canonical cell cycle arrest. Rev-erbα modulates circadian rhythm by downregulating the central circadian regulatory protein Bmal1, but this pathway did not play a central role in Rev-erbα control of cell growth. Additionally, while Rev-erbα has a well-described role in heme metabolism and subsequent support of mitochondria respiration, this pathway was not directly altered in Myc-driven liver cancer cells. Rather, knockdown of Rev-erbα was associated with decreased glycolytic activity characterized by a decrease in intracellular lactate and extracellular lactate production as well as an increase in certain glycolytic intermediates. In addition to these glycolytic changes, the maximum respiratory capacity of cells lacking Rev-erbα increased, as measured by oxygen consumption. These data suggest a novel role for Rev-erbα in promoting the growth of cancer cells through modulation of glucose metabolism and a shift towards increased respiration, and imply that cancers with upregulated Myc and Rev-erbα may be good candidates for chronotherapy.

We thank the following funding sources: NIH R01CA57341, LLS 6106-14.

Citation Format: Brian J. Altman, Annie Hsieh, Arvin M. Gouw, Zachary E. Stine, Anand Venkataraman, David I. Bellovin, Sharon J. Diskin, Wenyun Lu, Sisi Zhang, Dean W. Felsher, John M. Maris, Mitchell A. Lazar, Joshua D. Rabinowitz, John B. Hogenesch, Chi V. Dang. Rev-erbα modulates Myc-driven cancer cell growth and altered metabolism. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2953. doi:10.1158/1538-7445.AM2014-2953

Age of diabetes diagnosis and diabetes duration associate with glycated haemoglobin

An earlier age of diagnosis (r=-0.28, p<0.0001) and longer duration of type 2 diabetes (r=0.26, p<0.0001) were each found to correlate with higher HbA1c level, on analysis of a diabetes centre database in people under regular shared care. When combined, these biological variables strongly associate with the current HbA1c level.

Abstract 4616: Oncogenic c- and N-Myc disrupt circadian rhythm

Circadian rhythms are regulated by feedback loops comprising a network of factors that regulate Clock-associated genes. Chronotherapy seeks to take advantage of altered circadian rhythms in some cancers to better time administration of treatments to increase efficacy and reduce toxicity. Taking advantage of cancers that have substantially different circadian rhythms, or are ‘out of phase’, with normal tissues, could open a wide therapeutic window to make them vulnerable to chemotherapy or targeted drugs at different times than normal tissue. However, there is currently no basis to identify which cancers have disrupted circadian rhythms and would be amenable to chronotherapy. c- and N-Myc are oncogenic transcription factors translocated or amplified in many cancers. While the role of Myc in circadian rhythm is currently unknown, it may affect circadian rhythm by binding to the same E-box promoter regions used by the central regulators of circadian rhythm, Clock/Bmal1. Additionally, Myc increases NAD+ levels through upregulation of NAMPT, and NAD+ is a crucial cofactor in the activity of the circadian regulator Sirt1. Thus, we hypothesized that Myc may disrupt circadian rhythm through two mechanisms: inappropriate engagement of E-box promoters and also upregulation of NAMPT leading to dysregulated Sirt1 activity.

Here we show in neuroblastoma, osteosarcoma, and hepatocellular carcinoma cells that overexpressed Myc specifically upregulated the negative circadian regulator Rev-erbα, which in turn decreased expression of Bmal1. Inhibition of NAMPT downstream of Myc upregulation also led to major perturbations in circadian gene expression, suggesting a role for NAD modulation downstream of Myc in disruption of circadian rhythm. Importantly, My-expressing cells showed dramatically disrupted circadian oscillations, which could be partially rescued by inhibiting expression of Rev-erbα. Together, these data suggest that Myc-driven cancers have altered circadian oscillation due to upregulation of Rev-erbα and NAMPT, and that cancers driven by Myc may thus be good candidates for chronotherapy.

We thank the following funding sources: NIH R01CA051497, R01CA57341, LLS 636311

Citation Format: Brian J. Altman, Annie Hsieh, Arvin Gouw, Anand Venkataraman, Bo Li, David Bellovin, M. Celeste Simon, Dean Felsher, John Hogenesch, Chi V. Dang. Oncogenic c- and N-Myc disrupt circadian rhythm. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4616. doi:10.1158/1538-7445.AM2013-4616

Adenoviral delivery of osteoprotegerin ameliorates bone resorption in a mouse ovariectomy model of osteoporosis

Osteoprotegerin (OPG) regulates bone resorption by inhibiting osteoclast formation, function, and survival. The current studies employed a mouse ovariectomy (OVX) model of estrogen deficiency to investigate gene therapy with OPG as a means of preventing osteoporosis. Young adult females injected with a recombinant adenoviral (Ad) vector carrying cDNA of either full-length OPG or a fusion protein combining the hOPG ligand-binding domain with the human immunoglobulin constant domain (Ad-hOPG-Fc) developed serum OPG concentrations exceeding the threshold needed for efficacy. However, elevated circulating OPG levels were sustained for up to 18 months only in mice given Ad-hOPG-Fc. Administration of Ad-hOPG-Fc titers between 10(7) and 10(9) pfu yielded dose-dependent increases in serum OPG. Mice subjected to OVX or sham surgery followed by immediate treatment with Ad-hOPG-Fc had significantly more bone volume with reduced osteoclast numbers in axial and appendicular bones after 4 weeks. In contrast, animals given OVX and either a control vector or vehicle had significantly less bone than did comparably treated sham-operated mice. This study demonstrates that a single adenoviral gene transfer can produce persistent high-level OPG expression and shows that gene therapy to provide sustained delivery of OPG may prove useful in treating osteoporosis.

Pharmacokinetics and bioequivalence of a combined oral formulation of eniluracil, an inactivator of dihydropyrimidine dehydrogenase, and 5-fluorouracil in patients with advanced solid malignancies

BACKGROUND

This study was performed to evaluate the pharmacokinetics, bioequivalence, and feasibility of a combined oral formulation of 5-flurouracil (5-FU) and eniluracil (Glaxo Wellcome Inc., Research Triangle Park, North Carolina), an inactivator of dihydropyrimidine dehydrogenase (DPD). The rationale for developing a combined eniluracil/5-FU formulation oral dosing form is to simplify treatment with these agents, which has been performed using separate dosing forms, and decrease the probability of severe toxicity and/or suboptimal therapeutic results caused by inadvertently high or conversely insufficient 5-FU dosing.

PATIENTS AND METHODS

The trial was a randomized, three-way crossover bioequivalence study of three oral dosing forms of eniluracil/5-FU tablets in adults with solid malignancies. Each period consisted of two days of treatment and a five- to seven-day washout phase. Eniluracil at a dose of 20 mg, which results in maximal DPD inactivation, was administered twice daily on the first day and in the evening on the second day of each of the three treatments. On the morning of the second day, all patients received a total eniluracil dose of 20 mg orally and a total 5-FU dose of 2 mg orally as either separate tablets (treatment A) or combined eniluracil/5-FU tablets in two different strengths (2 tablets of eniluracil/5-FU at a strength (mg/mg) of 10/1 (treatment B) or 8 tablets at a strength of 2.5/0.25 (treatment C)). The pharmacokinetics of plasma 5-FU, eniluracil, and uracil, and the urinary excretion of eniluracil, 5-FU, uracil, and alpha-fluoro-beta-alanine (FBAL), were studied. To determine the bioequivalence of the combined eniluracil/5-FU dosing forms compared to the separate tablets, an analysis of variance on pharmacokinetic parameters reflecting eniluracil and 5-FU exposure was performed.

RESULTS

Thirty-nine patients with advanced solid malignancies had complete pharmacokinetic studies performed during treatments A, B, and C. The pharmacokinetics of eniluracil and 5-FU were similar among the three types of treatment. Both strengths of the combined eniluracil/5-FU dosing form and the separate dosing forms were bioequivalent. Mean values for terminal half-life, systemic clearance, and apparent volume of distribution for oral 5-FU during treatments A/B/C were 5.5/5.6/5.6 hours, 6.6/6.6/6.5 liters/hour, and 50.7/51.5/50.0 liters, respectively. The intersubject coefficient of variation for pharmacokinetic variables reflecting 5-FU exposure and clearance in treatments ranged from 23% to 33%. The urinary excretion of unchanged 5-FU over 24 hours following treatments A, B, and C averaged 52.2%, 56.1%, and 50.8'%, of the administered dose of 5-FU, respectively. Parameters reflecting DPD inhibition, including plasma uracil and urinary FBAL excretion following treatments A, B, and C were similar. Toxicity was generally mild and similar following all three types of treatments.

CONCLUSIONS

The pharmacokinetics of 5-FU and eniluracil were similar and met bioequivalence criteria following treatment with the separate oral formulations of 5-FU and eniluracil and two strengths of the combined formulation. The availability of a combined eniluracil/5-FU oral dosing form will likely simplify dosing and decrease the probability of severe toxicity or suboptimal therapeutic results caused by an inadvertent 5-FU overdose or insufficient 5-FU dosing in the case of separate oral formulations, thereby enhancing the overall feasibility and 0therapeutic index of oral 5-FU therapy.

Approaches to study of ischemia in bone

Ischemic osteonecrosis is a complication of certain traumatic and a number of idiopathic conditions. The course of the disease may result in collapse of the convex member of a joint and osteoarthritis, often requiring arthroplasty. Increasing incidence in young adults poses a challenge for development of long-term joint prostheses. Current status of research into the disease is discussed and three new models using intravital microscopy described. The first, an arterial occlusion (AO) model, creates ischemia by occluding the common iliac artery exclusively, avoiding direct trauma on other tissues in the limb. The second, a total occlusion (TO) model utilizes classical tourniquet occlusion of the thigh vessels. The third, a venous occlusion (VO) model, is also a tourniquet procedure but it blocks occlusion of the femoral artery with a protective sheath. Preliminary results from AO and TO studies are reported which show that reperfusion injury is detectible after ischemia doses as short as 4 h. This complication was confirmed by observation of leukocyte adherence, secondary ischemia, and abnormal vessel leakage. Also, a new quantitation of osteonecrosis is introduced whereby fluorescently-tagged dead osteocytes and computer-based image processing provide values for an "osteonecrosis index." Viewing of all vascular events is made possible by intravital microscopy through a bone chamber window implanted in rabbit tibias. It is proposed that such chronic visual techniques allow quantitation of events leading to osteonecrosis as well as the revascularization, resorption and bone apposition of creeping substitution which characterizes postischemia recovery.

Background ionizing radiation plays a minor role in the production of chromosome translocations in a control population

PURPOSE

To obtain a relationship between background chromosome translocation frequency and age with translocation frequency measured to a high statistical precision, and to identify the role of background ionizing radiation in the production of chromosome translocations in a control population.

MATERIALS AND METHODS

Lymphocytes from 35 healthy control individuals (15 females and 20 males) were scored, using fluorescence in situ hybridization, for the presence of chromosomal translocations. Translocation frequencies were measured to a high statistical precision (s.d. 25% or less for each individual). These control subjects were of varying ages, ranging from 0 (cord blood) to 98 years.

RESULTS

In a total of 521,492 metaphases (203,754 genome equivalent cells) scored, an average of 5,822 genome equivalent cells per individual, 764 translocations were observed in the 35 individuals. The translocation frequencies ranged from 0 (for cord blood) to 0.0167 (for a 98 year old) translocations per cell. The average age and translocation frequency was 50 years and 0.004 translocations per cell, respectively. The best fit of the relationship between translocations and age was: Y=7x10(-4)+6.9x10(-6)A+1.35x10(-6)A2, which does not obey the linear relationship expected from chronic background radiation alone. The curvilinear relationship observed clearly shows that other endogenous and exogenous clastogens or clastogenic events, in addition to radiation, serve to generate chromosome translocations in control populations.

CONCLUSION

The background translocation frequency in control individuals follows a curvilinear relationship with age. No significant variation was observed between individuals of the same age. Clastogenic processes of normal aging and physiological factors in additional to ionizing radiation play a major role in the production of chromosome translocations in a control population. Background radiation, however, appears to play a minor role in chromosome translocation production in control individuals living near sea level.

Assessment of regional wall motion abnormalities with real-time 3-dimensional echocardiography

Accurate characterization of regional wall motion abnormalities requires a thorough evaluation of the entire left ventricle (LV). Although 2-dimensional echocardiography is frequently used for this purpose, the inability of tomographic techniques to record the complete endocardial surface is a limitation. Three-dimensional echocardiography, with real-time volumetric imaging, has the potential to overcome this limitation by capturing the entire volume of the LV and displaying it in a cineloop mode. The purpose of this study was to assess the feasibility of using real-time 3-dimensional (RT3D) echocardiography to detect regional wall motion abnormalities in patients with abnormal LV function and to develop a scheme for the systematic evaluation of wall motion by using the 3-dimensional data set. Twenty-six patients with high-quality 2-dimensional echo images and at least 1 regional wall motion abnormality were examined with RT3D echocardiography. For 2-dimensional echocardiography, wall motion was analyzed with a 16-segment model and graded on a 4-point scale from normal (1) to dyskinetic (4), from which a wall motion score index was calculated. Individual segments were then grouped into regions (anterior, inferoposterior, lateral, and apical) and the number of regional wall motion abnormalities was determined. The RT3D echocardiogram was recorded as a volumetric, pyramid-shaped data set that contained the entire LV. Digital images, consisting of a single cardiac cycle cineloop, were analyzed off-line with a computerized display of the apical projection. Two intersecting orthogonal apical projections were simultaneously displayed in cineloop mode, each independently tilted to optimize orientation and endocardial definition. The 2 planes were then slowly rotated about the major axis to visualize the entire LV endocardium. Wall motion was then graded in 6 equally spaced views, separated by 30 degrees, yielding 36 segments per patient. A higher percentage of segments were visualized with 2-dimensional versus RT3D echocardiography (97% vs 83%, respectively, P <.001). With the use of the 2-dimensional echocardiographic results as the standard, RT3D echocardiography detected 55 (96%) of 57 regional wall motion abnormalities. Analysis of the RT3D echocardiograms resulted in 3 false-negative and 5 false-positive findings. The total number of regional wall motion abnormalities was correctly classified by RT3D echocardiography in 19 (73%) of 26 patients. RT3D echocardiography detected 11 of 13 anterior, 19 of 20 inferoposterior, 9 of 9 lateral, and 15 of 15 apical wall motion abnormalities. An excellent correlation was found between the 2 techniques for assessment of the regional wall motion score index (r = 0.89, P <.001). This initial clinical study demonstrates the feasibility and potential advantages of RT3D echocardiography for the assessment of regional LV function. Compared with 2-dimensional echocardiography, this new method permits recording of the entire LV in a single beat, allowing the extent and location of the regional wall motion abnormalities to be determined.

Phase I study of vinorelbine and ifosfamide in advanced non-small-cell lung cancer

PURPOSE

We designed a phase I dose-escalation study of vinorelbine on a novel (daily-times-three) schedule with ifosfamide with granulocyte colony-stimulating factor (G-CSF) support to define the dose-limiting toxicity (DLT) and maximum-tolerated dose (MTD) of vinorelbine in this combination.

PATIENTS AND METHODS

Cohorts of patients with stage IIIB or IV non-small-cell lung cancer (NSCLC) and no prior chemotherapy received vinorelbine starting at 15 mg/m2 on days 1, 2, and 3, and ifosfamide starting at 2.0 g/m2 on days 1, 2, and 3 with G-CSF support for all patients. Cycles were repeated every 21 days. Plasma vinorelbine concentrations were also analyzed.

RESULTS

Forty-two patients were treated. The median age was 58 years (range, 34 to 75) and 41 had a performance status of 0 or 1. The DLT was neutropenia and sepsis at a maximum-administered vinorelbine dose of 35 mg/m2 for 3 days. The recommended phase II dose was vinorelbine 30 mg/m2 with ifosfamide 1.6 g/m2 both given on 3 consecutive days. The overall response rate was 40% (17 of 42; all partial responders). The median survival duration was 50 weeks, with a 1-year survival rate of 48%. Pharmacokinetic analysis showed that vinorelbine in this combination and on this schedule is cleared 1.5 to two times faster than in single-agent once-weekly studies.

CONCLUSION

Myelosuppression is the DLT of this regimen with no major subjective toxicities. With tolerable toxicity and an encouraging 1-year survival rate of 48%, further investigation of this new vinorelbine schedule is warranted in this and other combination regimens.

Calcific constructive pericarditis: a rare complication of CREST syndrome

This report describes a patient with limited cutaneous scleroderma in whom calcific constrictive pericarditis developed. This complication of limited cutaneous scleroderma has not been reported previously.

Antibiotic killing of bacteria: comparison of bacteria on surfaces and in liquid, growing and nongrowing

The minimum inhibitory concentrations of antibiotics for bacterial pathogens are derived from broth suspensions (broth dilution) and from nutrient surfaces (agar dilution). These concentrations may not apply when bacteria are on a nonnutrient surface such as in a foreign body infection. We compared bacteria (Staphylococcus epidermidis and Escherichia coli) broth suspension MBCs with MBCs of the same bacteria when on a nonnutrient surface in broth the growing and nongrowing phases. Bacteria growing on cotton surfaces were much less susceptible to antibiotic killing than when freely suspended in the liquid nutrient. These results alone, independent of host factors, would explain the failure of antibiotics to eradicate infections involving bacteria on foreign body surfaces. The resistance of bacteria to antibiotic killing is not caused by a lack of antibiotic penetration to the site of the bacteria, but by an altered state of the bacteria when they are associated with a surface.

Restenosis presented with unstable angina and myocardial infarction: one explanation for late cardiac events following directional coronary atherectomy

Three cases of restenosis after directional coronary atherectomy (DCA) presented with unstable angina and then myocardial infarction. Two of them were complicated with malignant ventricular dysrhythmia. A total or subtotal thrombotic occlusion at the DCA site was shown. This fulminating course of restenosis could partially explain the higher late cardiac morbidity and mortality after DCA than after percutaneous transluminal balloon angioplasty.

Long term and large-scale cultivation of human hepatoma Hep G2 cells in hollow fiber bioreactor

Long-term and large scale cultivation of an anchorage-dependent cell line using an industrial scale hollow fiber perfusion bioreactor is described. Hep G2 cells (a human hepatoma cell line) were cultivated in an Acusyst-P (Endotronic) with a total fiber surface area of 7.2 m2 6 x 1.2m2) to produce Hep G2 crude conditioned medium (CCM). Pretreatment of the cellulose acetate hollow fibers with collagen enhances the attachment of the anchorage-dependent cells. We have succeeded in growing the Hep G2 cells in an antibiotics- and serum-free IMDM medium, supplemented with 50 micrograms/ml of Hep G2 CCM protein at inoculation. The Hep G2 cells replicate and secrete CCM protein in quantities comparable to those produced in DMEM containing 10% fetal calf serum (FCS). The highest CCM protein productivity during the 80-day cultivation was 1.1 g/day with a total of 30 g of protein accumulated. Hep G2 CCM (20-40 micrograms protein/ml) was comparable to or even better than 10% FCS in supporting the growth of Molt-4 (a human T leukemia cell line) and FO (a mouse myeloma cell line) cells in vitro. The availability of this large amount of Hep G2 CCM will aid the further purification and characterization of growth factor(s) which could be used as serum substituents.

Nutrition and metabolic studies of methyl esters of dimeric fatty acids in the rat

Methyl esters of dimeric fatty acids were prepared by fractionating a mixture of conjugated linoleic and oleic acids that was heated for 24 hr at 300 C in the absence of air. Rats fed diets containing less than 1% dimers showed no significant difference (P less than 0.05) in the growth rate, feed efficiency, liver:body weight ratio, and lipid:liver weight ratio from those fed normal diets. A lymph cannulation study using 14C labeled dimers showed that ca. 0.4% of the dimers fed were absorbed within 12 hr and were transported as free acids in the lymph. Within a 28 hr period, 2% of the labeled dimers fed by gastric intubation were oxidized to 14CO2, and 1% radioactivity was recovered from the urine. The metabolism of methyl oleate appeared normal for rats prefed diets containing dimers.