Therapeutic antibodies can elicit unwanted immune responses in a subset of patients, which leads to the production of anti-drug antibodies (ADA). Some of these ADAs have been reported to effect the ...pharmacokinetics, efficacy and/or safety of the therapeutic antibodies. The sequence diversity of antibodies are generated by VDJ recombination and mutagenesis. While the antibody generation process can create a large candidate pool for identifying high-affinity antibodies, it also could produce sequences that are foreign to the human immune system. However, it is not clear how VDJ recombination and mutagenesis impact the clinical ADA rate of therapeutic antibodies. In this study, we identified a positive correlation between the clinical ADA rate and the number of introduced mutations in the antibody sequences. We also found that the use of rare V alleles in human-origin antibody therapeutics is associated with higher risk of immunogenicity. The results suggest that antibody engineering projects should start with frameworks that contain commonly used V alleles and prioritize antibody candidates with low number of mutations to reduce the risk of immunogenicity.
The cost of data movement in big-data systems motivates careful examination of near-data processing (NDP) frameworks. The concept of NDP was actively researched in the 1990s, but gained little ...commercial traction. After a decade-long dormancy, interest in this topic has spiked. A workshop on NDP was organized at MICRO-46 and was well attended. Given the interest, the organizers and keynote speakers have attempted to capture the key insights from the workshop into an article that can be widely disseminated. This article describes the many reasons why NDP is compelling today and identifies key upcoming challenges in realizing the potential of NDP.
Interest in investigating the role of the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis in the initiation and progression of experimentally induced carcinomas has arisen due to ...several observations in the human population. First, subjects with Laron syndrome who lack GH signaling have significantly lower rates of cancer than people who have normal GH signaling. Second, epidemiologic studies have found strong associations between elevated circulating IGF-1 and the incidence of several common cancers. Third, women who bear children early in life have a dramatically reduced risk of developing breast cancer, which may be due to differences in hormone levels including GH. These observations have motivated multiple studies that have experimentally altered activity of the GH/IGF-1 axis in the context of experimental carcinoma models in mice and rats. Most of these studies have utilized carcinoma models for four organ systems that are also frequent sites of carcinomas in humans: the mammary gland, prostate gland, liver, and colon. This review focuses on these studies and describes some of the most common genetic models used to alter the activity of the GH/IGF-1 axis in experimentally induced carcinomas. A recurring theme that emerges from these studies is that manipulations that reduce the activity of GH or mediators of GH action also inhibit carcinogenesis in multiple model systems.
Female SV40 C3(1) T-antigen (C3(1)/TAg) transgenic mice develop mammary tumors that are molecularly similar to human basal-like breast cancers with 100% incidence at 16 weeks of age. To determine the ...requirement for growth hormone (GH) signaling in these tumors, genetic crosses were used to create cohorts of female mice that were homozygous for a floxed growth hormone receptor (Ghr) gene and carried one copy each of the Rosa-Cre-ERT2 transgene and the C3(1)/TAg transgene (Ghrflox/flox; Rosa-Cre-ERT2; C3(1)/TAg+/0 mice). When the largest mammary tumor reached 200 mm3, mice were treated with tamoxifen to delete Ghr or with vehicle as a control. An additional group of Ghrflox/flox; C3(1)/TAg+/0 mice were also treated with tamoxifen when the largest mammary tumor reached 200 mm3 as a control for the effects of tamoxifen. After 3 weeks, tumors in mice in which Ghr was deleted began to shrink while vehicle and tamoxifen treatment control mouse tumors continued to grow. Pathological analysis of tumors revealed similar growth patterns and varying levels of necrosis throughout all groups. A decrease in cancer cell proliferation in Ghr-/- tumors relative to controls was observed as measured by Ki67 immunohistochemistry labeling index. These data suggest that even established C3(1)/TAg mammary tumors are dependent on the GH/IGF-1 axis.
Highlights ► The value of determining non-clinical immunogenicity is described. ► Methods for detecting immunogenicity are compared. ► A strategy for non-clinical immunogenicity assessment is ...presented.
Higher plants are well known for their value in affording clinically useful anticancer agents, with such compounds acting against cancer cells by a range of mechanisms of action. There remains a ...strong interest in the discovery and development of plant secondary metabolites as additional cancer chemotherapeutic lead compounds. In the present review, progress on the discovery of plant-derived compounds of the biflavonoid, lignan, sesquiterpene, steroid, and xanthone structural types is presented. Several potential anticancer leads of these types have been characterized from tropical plants collected in three countries as part of our ongoing collaborative multi-institutional project. Preliminary structure–activity relationships and work on in vivo testing and cellular mechanisms of action are also discussed. In addition, the relevant work reported by other groups on the same compound classes is included herein.
Abstract
Previously, we reported that N-methyl-N-nitrosourea (MNU)-induced mammary tumors could be established in mutant spontaneous dwarf rats (SDRs), which lack endogenous growth hormone (GH) by ...supplementing with exogenous GH, and almost all such tumors regressed upon GH withdrawal. When the highly inbred SDR line was outcrossed to wild-type (WT) Sprague-Dawley rats, MNU-induced mammary tumors could still be established in resulting outbred SDRs by supplementing with exogenous GH. However, unlike tumors in inbred SDRs, 65% of mammary tumors established in outbred SDRs continued growth after GH withdrawal. We further tested whether these tumors were more sensitive to doxorubicin than their WT counterparts. To accomplish this, MNU-induced mammary tumors were established in WT rats and in SDRs supplemented with exogenous GH. Once mammary tumors reached 1 cm3 in size, exogenous GH was withdrawn from SDRs, and the subset that harbored tumors that continued or resumed growth in the absence of GH were selected for doxorubicin treatment. Doxorubicin was then administered in 6 injections over 2 weeks at 2.5 mg/kg or 1.25 mg/kg for both the WT and SDR groups. The SDR mammary tumors that had been growing in the absence of GH regressed at both doxorubicin doses while WT tumors continued to grow robustly. The regression of SDR mammary tumors treated with 1.25 mg/kg doxorubicin was accompanied by reduced proliferation and dramatically higher apoptosis relative to the WT mammary tumors treated with 1.25 mg/kg doxorubicin. These data suggest that downregulating GH signaling may decrease the doxorubicin dose necessary to effectively treat breast cancer.
The forced swim test (FST) is a commonly used preclinical animal behavioural model for prediction of antidepressant activity in humans. While the FST may qualitatively predict efficacy, less is known ...about the quantitative translation of FST data to human efficacious doses. Assessing quantitative translation allows better predictions of human efficacious doses and a higher chance of success in the drug development process.
Dose-response and time-course FST experiments were carried out on mice using four marketed antidepressants (citalopram, desipramine, bupropion, desvenlafaxine) in addition to ketamine, all with varying mechanisms of action. Population pharmacokinetic (PK)/pharmacodynamic (PD) analysis methods were applied to analyse the PK and immobility data, and the accuracy of the translation of FST data to human doses was evaluated using both area under the curve (AUC) and concentration-based approaches.
The results showed that for the five antidepressants, average human AUC at clinically relevant doses were up to 38-fold higher than mouse AUC at doses associated with 50% of maximal efficacy in the FST (ED50). Using a concentration approach, human peak and trough drug concentrations at clinically relevant doses were generally associated with concentrations of at least 65% (EC65) and 20% (EC20) of maximal effect in mice, respectively.
The FST is a useful tool to predict antidepressant efficacy across a variety of drugs with different mechanisms of actions. However, human doses can be over-or under-predicted many fold when using the traditional approach of estimating based upon ED50 AUC in mice. It is recommended that a concentration approach be used, where concentrations associated with 80% (EC80) and 30% (EC30) of maximal effect in the mouse are used as general targets for human maximum and trough concentrations, respectively, in the prediction of clinically efficacious doses of new, potential antidepressant agents.
•The ability of mouse forced swim test to predict human doses was investigated.•PK/PD modelling was carried out on forced swim test data for 5 antidepressants.•Forced swim test has good predictive efficacy across different antidepressants.•Concentrations, instead of AUC, are better for predicting human efficacious doses.
During the past few years, a group of cyclopentabbenzofurans from the plant genus Aglaia has received broad scientific attention as interesting natural product lead compounds with potential ...anticancer and insecticidal activities. Since the first cyclopentabbenzofuran derivative, rocaglamide, from Aglaia elliptifolia, was found to exhibit antileukemic activity in a murine in vivo model, the genus Aglaia has been subjected to further investigation. Over 40 cyclopentabbenzofurans have been tested against different human cancer cell lines, and the cumulative results provide some important clues as to how to improve their activity through modification of their chemical structures. The semisynthesis and total synthesis of the cyclopentabbenzofurans have been conducted. Although the ultimate molecular target(s) responsible for their antiproliferative activity has not yet been identified, studies on their cellular mechanism of action have demonstrated that some of these compounds inhibit TNF-alpha or PMA-induced NF-kappaB activity in T-lymphocytes and induce apoptosis in different human cancer cell lines. Based on the published data thus far, cyclopentabbenzofurans offer excellent potential as therapeutic agent candidates in cancer chemotherapy, even if much work still remains to be done for their further development.
Sixteen polyketides belonging to diverse structural classes, including monomeric/dimeric tetrahydroxanthones and resorcylic acid lactones, were isolated from an organic extract of a fungal culture ...Setophoma terrestris (MSX45109) by bioactivity‐directed fractionation as part of a search for anticancer leads from filamentous fungi. Of these, six were new: penicillixanthone B (5), blennolide H (6), 11‐deoxyblennolide D (7), blennolide I (9), blennolide J (10), and pyrenomycin (16). The known compounds were: secalonic acid A (1), secalonic acid E (2), secalonic acid G (3), penicillixanthone A (4), paecilin B (8), aigialomycin A (11), hypothemycin (12), dihydrohypothemycin (13), pyrenochaetic acid C (14), and nidulalin B (15). The structures were elucidated by a set of spectroscopic and spectrometric techniques: the absolute configurations of compounds 1–10 were determined by ECD spectroscopy combined with time‐dependent density functional theory (TDDFT) calculations, whereas a modified Mosher's ester method was used for compound 16. The cytotoxic activities of compounds 1–15 against the MDA‐MB‐435 (melanoma) and SW‐620 (colon) cancer cell lines were evaluated. Compounds 1, 4, and 12 were the most potent, with IC50 values ranging from 0.16 to 2.14 μM. When tested against a panel of bacteria and fungi, compounds 3 and 5 showed promising activity against the Gram‐positive bacterium Micrococcus luteus, with MIC values of 5 and 15 μg mL–1, respectively.
Sixteen polyketides, six of them new, were isolated from a fungal culture (Setophoma terrestris). Cytotoxicity assays were used to develop structure–activity relationships amongst the series.
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