Anticancer Drugs

Plant‐derived anticancer drugs play a large role in anticancer pharmaceuticals. Through reviewing the four major types of plant anticancer drugs, namely vinca alkaloids, taxane diterpenoids, podophyllotoxin lignans, and camptothecin quinoline alkaloids, this article illustrates the development process, current status, existing challenges, and future perspective of the plant anticancer drug production. Moreover, this review explains how various biotechnologies, from the mature elicitation strategy to the “omics” techniques that are still undergoing development, can be applied to address the challenges in improving the production of the plant‐sourced anticancer drugs

Cancer cell expulsion of anticancer drugs through shedding of microvesicles: association with drug resistance and tumour survival

Microvesicles (MVs) are small (0.1-≤1 µm in diameter) heterogeneous vesicles released from cells constitutively or upon activation, that mediate intercellular communication. Multi-drug resistance (MDR) has been defined as the ability of cancer cells to survive after treatment with various drugs. However, the mechanism(s) used by cancer cells to evade apoptosis induced by anticancer drugs remain unclear and was the subject of our investigation. Here we report a novel mechanism of cancer cell expulsion of anticancer drugs through the release of MVs, followed by the recruitment of lysosomes to the site of release to repair the resulting damage. In addition, we show for the first time that inhibition of MV release by pretreatment of PC3M cells with the calpain inhibitor, calpeptin, sensitizes cancer cells to drug-elicited apoptosis mediated by the addition of methotrexate (MTX) and docetoxel (DOC) using at least 10-fold lower concentrations, both in vitro and in vivo. Treatment of cancer patients with MET or DOC leads to significant side effects due to the use of higher doses. Here we show that these drugs when administered together with calpeptin can be given at doses 100 times lower and still induce effective killing of target cancer cells. Overall our studies shed light on the role of MV release in cancer cell expulsion of anticancer drugs and subsequent evasion and survival from apoptosis and suggest new combination therapies for existing cancer drugs.Peer reviewedFinal Accepted Versio

The rising cost of anticancer drugs in Australia

Background: Anticancer drugs are often expensive and are contributing to the growing cost of cancer care. Concerns have been raised about the effect rising costs may have on availability of new anticancer drugs. Aim: This study aims to determine the recent changes in the costs of anticancer drugs in Australia. Methods: Publicly available expenditure and prices paid by the Australian Pharmaceutical Benefits Scheme (PBS) for anticancer drugs from 2000 to 2012 were reviewed. The measures used to determine changes in cost were total PBS expenditure and average price paid by the PBS per prescription for anticancer drugs and for all PBS listed drugs. An estimated monthly price paid for newly listed anticancer drugs was also calculated. Results: Annual PBS expenditure on anticancer drugs rose from A$65 million in 1999–2000 to A$466 million in 2011–2012; an average increase of 19% per annum. The average price paid by the PBS per anticancer drug prescription, adjusted for inflation, increased 133% from A$337 to A$786. The real average annual increase in the price per anticancer drug prescription was more than double that for all other PBS drugs combined (7.6% vs 2.8%, difference 4.8%, 95% confidence interval −0.4% to 10.1%, P = 0.07). The median price for a month’s treatment of the new anticancer drugs listed was A$4919 (range A$1003 to A$12 578, 2012 prices). Conclusions: PBS expenditure and the price of anticancer drugs in Australia rose substantially from 2000 to 2012. Dealing with these burgeoning costs will be a major challenge for our health system and for those affected by cancer

Anticancer Drugs

The development of a new anticancer drug with a novel structure and unique mechanism of action is an important event, especially when the drug plays a clear role in improving the outcome for cancer patients. No drug fits this description better than Taxol. However, during the early phases of its development, there was little interest in the drug, particularly in the medical community. The story of Taxol is long and fascinating, and includes many examples in which the drug could have been dropped, resulting in its antitumor activity never being available to patients. It was 21 years between the original landmark paper on the isolation and structural determination of Taxol and its approval in 1992 by the FDA for its use in the treatment of ovarian cancer.R01 CA077263/CA/NCI NIH HHS/United StatesSA-43-PH-4322/PH/PHPPO CDC HHS/United States2015-05-01T00:00:00

Docking and QSAR Studies of Camptothecin Derivatives as Inhibitor of DNA Topoisomerase-I

Camptothecin (CPT) is a cytotoxic quinoline alkaloid which inhibits the DNA enzyme Topoisomerase-I (Topo-I) and has shown remarkable anticancer activity in preliminary clinical trials. The major limitation is its low solubility and high adverse reaction. In the studied work, we performed molecular docking of CPT derivatives against Topo-I and developed the quantitative structure activity relationship (QSAR) model for anticancer activity screening. For QSAR, we used CPT and other anticancer drugs with its IC50 values. We used a total of forty seven anticancer drugs as training set and eight compounds as test set and thirty derivatives of CPT as query set. Total of fifty two chemical descriptors were used for the quantitative data calculation. Only four showed good correlation with the experimental activity. Forward feed regression method was used for development of multiple linear regression (MLR) QSAR model. Model showed acceptable regression coefficient (r2) 0.89 (i.e., 89% of correlation) and cross validation coefficient (rCV2) 0.86 (i.e., 86 % of prediction accuracy). After drug likeness test, ten compounds namely, MSB3a, MSB3b, MSB19, MSB22L, MSB22M, MSB22O, MSB22R, MSB25D, MSB37G and MSB39D, showed promising predicted anticancer activity and drug likeness properties. Out of ten, only six compounds namely, MSB19, MSB22L, MSBM, MSB22O, MSB22R and MSB37D indicate two times more activity than the parent CPT compound. In molecular docking studies, all the identified active CPT derivatives showed high binding affinity with Topo-I. QSAR study indicates that connectivity index, electron affinity, mol.wt. & ether group count highly contribute to inhibitory activity of CPT derivatives. These results can offer useful references for directing the molecular design of Topo-I inhibitor with improved anticancer activity.
&#xa

Glutathione-s-transferase modified electrodes for detecting anticancer drugs

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.bios.2014.02.070. © 2014. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/With the fast growth of cancer research, new analytical methods are needed to measure anticancer drugs. This is usually accomplished by using sophisticated analytical instruments. Biosensors are attractive candidates for measuring anticancer drugs, but currently few biosensors can achieve this goal. In particular, it is challenging to have a general method to monitor various types of anticancer drugs with different structures. In this work, a biosensor was developed to detect anticancer drugs by modifying carbon paste electrodes with glutathione-s-transferase (GST) enzymes. GST is widely studied in the metabolism of xenobiotics and is a major contributing factor in resistance to anticancer drugs. The measurement of anticancer drugs is based on competition between 1-chloro-2,4-dinitrobenzene (CDNB) and the drugs for the GST enzyme in the electrochemical potential at 0.1 V vs. Ag/AgCl by square wave voltammetry (SWV) or using a colorimetric method. The sensor shows a detection limit of 8.8 μM cisplatin and exhibits relatively long life time in daily measurements.University of Waterloo || Natural Sciences and Engineering Research Council || Emerging Leaders in the Americas Program |

Unleashing the full potential of Hsp90 inhibitors as cancer therapeutics through simultaneous inactivation of Hsp90, Grp94, and TRAP1

Cancer therapeutics: Extending a drug's reach A new drug that blocks heat shock proteins (HSPs), helper proteins that are co-opted by cancer cells to promote tumor growth, shows promise for cancer treatment. Several drugs have targeted HSPs, since cancer cells are known to hijack these helper proteins to shield themselves from destruction by the body. However, the drugs have had limited success. Hye-Kyung Park and Byoung Heon Kang at Ulsan National Institutes of Science and Technology in South Korea and coworkers noticed that the drugs were not absorbed into mitochondria, a key cellular compartment, and HSPs in this compartment were therefore not being blocked. They identified a new HSP inhibitor that can reach every cellular compartment and inhibit all HSPs. Testing in mice showed that this inhibitor effectively triggered death of tumor cells, and therefore shows promise for anti-cancer therapy. The Hsp90 family proteins Hsp90, Grp94, and TRAP1 are present in the cell cytoplasm, endoplasmic reticulum, and mitochondria, respectively; all play important roles in tumorigenesis by regulating protein homeostasis in response to stress. Thus, simultaneous inhibition of all Hsp90 paralogs is a reasonable strategy for cancer therapy. However, since the existing pan-Hsp90 inhibitor does not accumulate in mitochondria, the potential anticancer activity of pan-Hsp90 inhibition has not yet been fully examined in vivo. Analysis of The Cancer Genome Atlas database revealed that all Hsp90 paralogs were upregulated in prostate cancer. Inactivation of all Hsp90 paralogs induced mitochondrial dysfunction, increased cytosolic calcium, and activated calcineurin. Active calcineurin blocked prosurvival heat shock responses upon Hsp90 inhibition by preventing nuclear translocation of HSF1. The purine scaffold derivative DN401 inhibited all Hsp90 paralogs simultaneously and showed stronger anticancer activity than other Hsp90 inhibitors. Pan-Hsp90 inhibition increased cytotoxicity and suppressed mechanisms that protect cancer cells, suggesting that it is a feasible strategy for the development of potent anticancer drugs. The mitochondria-permeable drug DN401 is a newly identified in vivo pan-Hsp90 inhibitor with potent anticancer activity

Current applications and future potential for bioinorganic chemistry in the development of anticancer drugs

This review illustrates notable recent progress in the field of medicinal bioinorganic chemistry as many new approaches to the design of innovative metal-based anticancer drugs are emerging. Current research addressing the problems associated with platinum drugs has focused on other metal-based therapeutics that have different modes of action and on prodrug and targeting strategies in an effort to diminish the side-effects of cisplatin chemotherapy

Advances in the development of hybrid anticancer drugs

Introduction: Hybrid anticancer drugs are of great therapeutic interests as they can potentially overcome most of the pharmacokinetic drawbacks encountered when using conventional anticancer drugs. In fact, the future of hybrid anticancer drugs is very bright for the discovery of highly potent and selective molecules that triggers two or more cytocidal pharmacological mechanisms of action acting in synergy to inhibit cancer tumor growth. Areas covered: This review represents the most advanced and recent data in the field of hybrid anticancer agents covering mainly the past 5 years of research. It also accounts for other significant reviews already published on the topic of anticancer hybrids. The review showcases the research that is at the leading edge of hybrid anticancer drug discovery. The main areas covered by the present review are: DNA alkylating agent hybrids (e.g., platinum(II), nitrogen mustard, etc.), vitamin-D receptor, agonist–histone deacetylase inhibitors, combi-molecule therapies and other types of hybrid anticancer agents. Expert opinion: The current development in the field describes strategies that have never been used before for the design of hybrid anticancer drugs. The information currently available and described in this section allows us to identify the main parameters required to design such molecules. It also provides a clear view of the future directions that must be explored for the successful development and discovery of useful hybrid anticancer drugs