Development Of New Chemotherapeutics Research Articles

Overview of the New Bioactive Heterocycles as Targeting Topoisomerase Inhibitors Useful Against Colon Cancer.

Colorectal cancer (CRC) is the third most common cancer globally, with high mortality. Metastatic CRC is incurable in most cases, and multiple drug therapy can increase patients' life expectancy by 2 to 3 years. Efforts are being made to understand the relationship between topoisomerase enzymes and colorectal cancer. Some studies have shown that higher expression of these enzymes is correlated to a poor prognosis for this type of cancer. One of the primary drugs used in the treatment of CRC is Irinotecan, which can be used in monotherapy or, more commonly, in therapeutic schemes such as FOLFIRI (Fluorouracil, Leucovorin, and Irinotecan) and CAPIRI (Capecitabine and Irinotecan). Like Camptothecin, Irinotecan and other compounds have a mechanism of action based on the formation of a ternary complex with topoisomerase I and DNA providing damage to it, therefore leading to cell death. Thus, this review focused on the principal works published in the last ten years that demonstrate a correlation between the inhibition of different isoforms of topoisomerase and in vitro cytotoxic activity against CRC by natural products, semisynthetic and synthetic compounds of pyridine, quinoline, acridine, imidazoles, indoles, and metal complexes. The results revealed that natural compounds, semisynthetic and synthetic derivatives showed potential in vitro cytotoxicity against several colon cancer cell lines, and this activity was often accompanied by the ability to inhibit both isoforms of topoisomerase (I and II), highlighting that these enzymes can be promising targets for the development of new chemotherapy against CRC. Pyridine analogs were considered the most promising for this study, while the evaluation of the real potential of natural products was limited by the lack of information in their work. Moreover, the complexes, although promising, presented as the main limitation the lack of selectivity.

Cuscuta reflexa Possess Potent Inhibitory Activity Against Human Malaria Parasite: An In Vitro and In Vivo Study

Drug resistance to practicallyallantimalarialdrugs in use necessitate the development of new chemotherapeutics against malaria. In this aspect, traditionally used plants with folklore reputation are the pillar for drug discovery. Cuscuta reflexa being traditionally used in the treatment of malaria in Odisha, India we aimed to experimentally validate its antimalarial potential. Different solvent extracts of C. reflexa or column fractions from a promising solvent extract were evaluated for in vitro anti-plasmodial activity against Plasmodium falciparum strain Pf3D7. Potent fractions were further evaluated for inhibition of parasite growth against different drug resistant strains. Safety of these fractions was determined by in vitro cyto-toxicity, and therapeutic effectiveness was evaluated by suppression of parasitemia and improvement in survival of experimental mice. Besides, their immunomodulatory effect was investigated in Pf-antigen stimulated RAW cells. GCMS fingerprints of active fractions was determined. Column separation of methanol extract which showed the highest in vitro antiplasmodial activity (IC50 = 14.48μg/ml) resulted in eleven fractions, three of which (F2, F3, and F4) had anti-plasmodial IC50 ranging from ≤ 10 to 2.2μg/ml against various P. falciparum strains with no demonstration of in vitro cytotoxicity. F4 displayed the highest in vivo parasite suppression, and had a mean survival time similar to artesunate (19.3 vs. 20.6days). These fractions significantly modulated expression of inflammatory cytokines in Pf-antigen stimulated RAW cells. The findings of the study confirm the antimalarial potential of C. reflexa. Exploration of phyto-molecules in GCMS fingerprints of active fractions is warranted for possible identification of lead anti-malarial phyto-drugs.

Abstract 1655: Discovery of a novel PP2A activator as a potential therapeutic for FOLFOX resistant colon cancer

Abstract Protein phosphatase 2A (PP2A) is a diverse serine/threonine phosphatase that accounts for 50-70% of all serine/threonine phosphorylation in the cell. Due to the inactivation of PP2A in cancer, many of the cellular processes that PP2A regulates are aimed towards tumor progression. As such, the therapeutic targeting of PP2A in cancer is becoming a popular research avenue in the development of new chemotherapeutics. Currently, there have been a few PP2A activators observed to inhibit tumor progression in vitro and in vivo; however, these compounds have shown to have poor bioavailability, such as NSC49L, or uncertainty towards their ability to activate PP2A, as is the case with iHAP1. These hindrances demonstrate a need for further optimization of these molecules in order to produce a PP2A activator capable of inhibiting cancer without these limitations. As such, we have designed a series of compounds utilizing molecular modeling and fragment-based drug design based upon the known PP2A activators, NSC49L and iHAP1. These compounds were assessed for their ability to inhibit colon cancer (CRC) cells and FOLFOX-resistant CRC cells, where PPA24 was identified as the lead compound. The dose-response curves identified IC50 values in the range of 2.36-6.75µM for PPA24 across four CRC cell lines (HCT116, HT29, DLD1, and SW480) and two FOLFOX-resistant CRC cell lines (FOLFOX-HCT116 and FOLFOX-HT29), displaying more cytotoxicity than both the parent compounds and the other compounds in the series. Molecular docking recognized lower binding energies occurring during the association of PP2A with PPA24 than with either NSC49L or iHAP1. When examining the in vitro effect of PPA24 on stimulating PP2A activation, it was found that PPA24 significantly induced PP2A activity 2-3-fold higher than NSC49L or iHAP1. Likewise, PPA24 was able to induce apoptosis dose-dependently in both CRC and FOLFOX-resistant CRC cells. As PP2A is known for regulating the cell cycle progression, further exploration revealed PPA24 able to induce cell cycle arrest at the G2/M phase. And PP2A, being known as a regulator for many cellular processes, can be activated to assist in the degradation and inactivation of many signaling proteins such as c-myc, GSK3β, and ERK, which was observed in CRC cells treated with PPA24. Together, these results signify the potential of PPA24 to act as a novel PP2A activator in the treatment of CRC and FOLFOX-resistant CRC. Citation Format: Hannah Johnson, Amandeep Singh, Asif Raza, Congzhou M. Sha, Nikolay V. Dokholyan, Satya Narayan, Arun K. Sharma. Discovery of a novel PP2A activator as a potential therapeutic for FOLFOX resistant colon cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1655.

Synthesis of Palladium-Catalysed C-C Bond Forming 5-Chloro Quinolines via Suzuki-Miyaura Coupling; Anti-Pancreatic Cancer Screening on PANC-1 Cell Lines.

Pancreatic cancer is the most severe among other cancers due to its late detection and less chance of survivability. Heterocycles are proven ring systems in the treatment of various cancers and this is due to the presence of two biodynamic molecules combined, which have a greater synergistic efficacy in many anticancer drugs. Quinoline and pyridine ring systems are brought together to obtain greater potency and this is achieved by coupling both using Pd-catalyst, and in the present investigation, Suzuki-Miyaura coupling (SMC) reactions are adopted to generate potent molecular entities. Pancreatic cancer is difficult to treat due to overexpression of the VEGFR2 protein. VEGFR2 is targeted to design the molecules of quinoline-coupled pyridine moieties and is docked to evaluate the protein-ligand interaction at the binding site. The binding affinity of conjugates revealed the potency and capability of ligands to inhibit the VEGFR2 pathway. The in-silico ADMET properties determined their inherent pharmacokinetic feasibility. The synthesized conjugates have been evaluated by MTT assay against the human pancreatic cancer cell lines (PANC-1). Among the series, compounds 5d, 5e, and 5h exhibited a greater inhibitory activity against the cell lines with an IC50 value of 82.32±1.38, 54.74±1.18 and 80.35±1.68 μM. In the present exploration, 5e exhibited greater inhibitory activity and it could be a promising lead for the development of new chemotherapeutics against pancreatic cancer.

Quinoline–1,3,4-Oxadiazole Conjugates: Synthesis, Anticancer Evaluation, and Molecular Modelling Studies

Cancer continues to have overwhelming impacts on human health and the development of new chemotherapeutics. Molecular hybridization has thus been valued as a structure-based drug design approach to drugs with enhanced efficacy. Herein, we report the multistep synthesis of quinoline–2-mercapto-1,3,4-oxadiazole conjugates and their cytotoxicity evaluation. Compound 4j 2-[(5-bromopentyl)thio]-5-[(quinolin-8-yloxy)methyl]-1,3,4-oxadiazole showed the best cytotoxicity to pancreatic (MIA PaCa-2) and colorectal (HCT116) cancer cells with IC50 values of 29.19 ± 0.99 and 75.10 ± 1.87 µM, respectively. The compound is also less cytotoxic to non-cancerous human primary dermal fibroblast cells with IC50 = 91.87 ± 1.29 µM compared to the parent compound 8-hydroxyquinoline (IC50 = 72.36 ± 4.23 µM). ADME properties prediction suggested the drug-likeness of potent compounds while molecular docking and molecular dynamics simulations with doublecortin-like kinase (DCLK1) revealed the compounds’ stable binding interactions at the kinase domain. Overall, the results illuminate compound 4j as a structural model to furnish new cytotoxic agents against pancreatic and colorectal cancer.

A novel 3D in vitro tissue model for bone‐metastasized breast cancer: A preclinical tool in drug discovery and testing

AbstractBone metastasis is a frequent occurrence following breast cancer. The bone‐tumor microenvironment is heterogeneous and complicated to recapitulate. The development of new chemotherapeutics is ineffective partly due to a lack of precise in vitro tissue models. We developed a three‐dimensional (3D) bone‐tumor interface model for customized chemotherapeutic screening. It comprises a plasma‐modified electrospun mat seeded with osteoblasts to mimic a bone tissue, with a cell‐seeded hydrogel layer containing more and less aggressive or noncancerous cells on top, mimicking the tumor compartment. By screening the model with doxorubicin, we observed different migratory behaviors, with IC50 values that were largely in accordance with those cell lines' characteristics. Our 3D model reproduces the bone microenvironment and has great potential as a drug screening tool for personalized medicine.

Acetylenic Synthetic Betulin Derivatives Inhibit Akt and Erk Kinases Activity, Trigger Apoptosis and Suppress Proliferation of Neuroblastoma and Rhabdomyosarcoma Cell Lines.

Neuroblastoma (NB) and rhabdomyosarcoma (RMS), the most common pediatric extracranial solid tumors, still represent an important clinical challenge since no effective treatment is available for metastatic and recurrent disease. Hence, there is an urgent need for the development of new chemotherapeutics to improve the outcome of patients. Betulin (Bet), a triterpenoid from the bark of birches, demonstrated interesting anti-cancer potential. The modification of natural phytochemicals with evidenced anti-tumor activity, including Bet, is one of the methods of receiving new compounds for potential implementation in oncological treatment. Here, we showed that two acetylenic synthetic Bet derivatives (ASBDs), EB5 and EB25/1, reduced the viability and proliferation of SK-N-AS and TE671 cells, as measured by MTT and BrdU tests, respectively. Moreover, ASBDs were also more cytotoxic than temozolomide (TMZ) and cisplatin (cis-diaminedichloroplatinum [II], CDDP) in vitro, and the combination of EB5 with CDDP enhanced anti-cancer effects. We also showed the slowdown of cell cycle progression at S/G2 phases mediated by EB5 using FACS flow cytometry. The decreased viability and proliferation of pediatric cancers cells after treatment with ASBDs was linked to the reduced activity of kinases Akt, Erk1/2 and p38 and the induction of apoptosis, as investigated using Western blotting and FACS. In addition, in silico analyses of the ADMET profile found EB5 to be a promising anti-cancer drug candidate that would benefit from further investigation.

Identification of an orally active carbazole aminoalcohol derivative with broad-spectrum anti-animal trypanosomiasis activity

Animal trypanosomiasis, caused by the members of subgenus Trypanozoon (Trypanosoma brucei brucei, T. evansi and T. equiperdum), has reduced animal productivity leading to significant negative economic impacts in endemic regions. Due to limited drug discovery and the emergence of drug-resistance over many recent decades, novel and effective compounds against animal trypanosomiasis are urgently required. This study was conducted to evaluate the antitrypanosomal potential of a batch of carbazole aminoalcohol derivatives. Among them, we found that the most effective compound was H1402, which exhibited potent trypanocidal efficacy against the bloodstream-form of T. b. brucei (EC50 = 0.73 ± 0.05 µM) and presented low cytotoxicity against two mammalian cell lines with CC50 > 30 µM. Using a murine model of acute infection, oral administration with H1402 demonstrated a complete clearance of T. b. brucei and all the infected mice were cured when they were treated twice daily for 5 days at a dose of 100 mg/kg. Furthermore, parasites were not detected in mice infected with T. evansi and T. equiperdum (the causative agents of surra and dourine, respectively, in animals) within 30 days following the same regimen with H1402. In addition, H1402 caused severe morphological and ultrastructural destruction to trypanosomes, as well as causing phosphatidylserine externalization, which are suggested to be the most likely cause of cell death. Overall, the present data demonstrated that H1402 could be promising as a rapid, safe and orally active lead compound for the development of new chemotherapeutics for animal trypanosomiasis.

Etoposide Loaded SPION-PNIPAM Nanoparticles Improve the in vitro Therapeutic Outcome on Metastatic Prostate Cancer Cells via Enhanced Apoptosis.

Prostate cancer is among the leading causes of death worldwide because its metastatic form is a deadly disease. Therefore, the development of new chemotherapeutics is of immense importance. Nanoparticle technology seems to provide diverse options in this regard. Therefore, poly(N-isopropylacrylamide) (PNIPAM) coated superparamagnetic iron oxide nanoparticles (SPION) loaded with Etoposide were prepared in small sizes (57 nm) and with 3.5 % drug content to improve the efficiency of Etoposide in prostate cancer therapy. Sustained release of the drug was achieved, which found to be sensitive to low pH and high temperature. The anti-growth activity of SPION-PNIPAM-Etoposide formulation against metastatic prostate cancer cells (PC-3, LNCaP) were investigated by SRB assay, then, confirmed by ATP assay. Mode of cell death was evaluated by using flow cytometry analyses. A significant improvement of nanoformulated drug was observed at 5-10 μg/ml doses of the drug in both cell lines. More importantly, this formulation enhanced the cytotoxic effect of Etoposide on PC-3 cells, which is considered more resistant to Etoposide than LNCaP and reduced the IC50 value by 55 % reaching to 4.5 μg drug/ml, which is a very significant improvement in the literature. It was clearly shown that nanoformulated drug provided about 3-fold increases in caspase-dependent early apoptotic cells in PC-3 cells. The novel formulation seems to successfully cause cell death of especially PC-3 metastatic prostate cancer cells. It should therefore be taken into consideration for further animal studies as a novel potent anticancer agent.

Aldehyde biphenyl chalcones induce immunogenic apoptotic-like cell death and are promising new safe compounds against a wide range of hematologic cancers.

Aim:Investigate the apoptotic mechanisms of two new aldehyde biphenyl chalcones on leukemia cells.Materials& methods:From a series of 71 new chalcones, we selected the two most cytotoxic.Results: JA3 and JA7 were cytotoxic not only against hematological malignancies but also against solid tumor and cancer stem cells, yet with no toxicity to normal cells. Moreover, they induced immunogenic apoptotic-like cell death independently of promyelocytic leukemia protein, with extensive mitochondrial damages downstream of endoplasmic reticulum stress. Preventing endoplasmic reticulumstress and the upregulation of proapoptotic machinery inhibited JA3- and JA7-induced cell death. Likewise, blocking receptor Fas protected cells from killing. They increased the antileukemic effect of cytarabine and vincristine and killed leukemic cells collected from patients with different acute leukemia subtypes. Conclusion:JA3 and JA7 represent new promising prototypes for the development of new chemotherapeutics.

Mechanisms Of Dermatophyte Resistance To Antifungal Substances

Abstract Dermatophytes are pathogenic fungi with high affinity for keratinised structures present in nails, skin, and hair causing superficial infections known as skin mycoses or dermatomycoses. The disease is characterised by variable prognosis. Its clinical picture is largely dependent on the immune status of the host and can range from local skin or subcutaneous infections to invasive, disseminated, and life-threatening infections. In the first decades of the 20th century, the first concerns were raised about the growing prevalence of fungal infections in humans, which was ascribed to various environmental factors and anthropopressure. Consequently, the first therapeutic attempts were made to treat these infections. At present, at least several different groups of antifungal drugs are available for medical treatment. Nevertheless, the overlapping mechanisms of action of these substances and discontinuation of therapy by patients may contribute to the emergence of resistance of strains, including multi-drug resistance. The aim of this study is to review the literature focused on the mechanisms of resistance developed by dermatophytes to antifungal substances. Through evolution, these fungi have developed complex cellular response systems comprising elements of the environment-cell signalling system, responses to stressors, and tolerance to harmful chemical substances. Such stimuli as exposure of dermatophytes to an antifungal drug, damage to their cell wall, and disturbances in the osmolarity of the environment with generation of reactive oxygen species can be activators of signalling pathways targeted at mitigation of the effects of sudden cellular stress. A majority of molecular mechanisms underlying the response to these stressors also constitute a mechanism of tolerance and resistance to antifungal substances. In the future, elucidation of these mechanisms may lead to development of new chemotherapeutics that will become a key strategy in the treatment of dermatophyte strains exhibiting resistance to currently available antifungal drugs. 1. Introduction. 2. Current antifungal drugs. 3. Exposure of the pathogen to drugs, stress response, and adaptation. 4. Mechanisms of drug efflux from the cell. 5. Mechanisms of drug detoxification. 6. Transcriptional modulation of signalling pathway genes. 7. Role of heat shock proteins in drug resistance. 8. Mutations in target enzyme genes inducing drug resistance. 9. Structural elements of the cell contributing to drug resistance. 10. Summary

Known and novel ocular toxicities of biologics, targeted agents, and traditional chemotherapeutics.

Increases in cancer with an aging population and the rapid development of new chemotherapeutics underscore the need for ophthalmologists to identify and manage potential ocular toxicities. This retrospective case series reports the ocular side effects of traditional and novel chemotherapeutic agents from a large center. The medical records of 3537 adult patients 18years and older who presented to an academic ophthalmology department on high-risk medications identified by ICD-9 search between January 2010 and February 2015 were reviewed. A cancer diagnosis, as well as a temporal association with chemotherapeutic use and ocular side effect, was deemed necessary for inclusion in the study. The main measures were ocular side effects in cancer patients taking chemotherapy, ocular imaging abnormalities, and the outcome of each side effect. Of the 161 oncology patients referred to the ophthalmology clinic for chemotherapeutic screening or ocular side effect, 31 (19.3%) were identified as having an ocular adverse reaction due to a novel or traditional chemotherapeutic medication. A novel flattening of the corneal curvature with hyperopic shift and corneal microcysts was identified in a patient taking the antibody-drug conjugate mirvetuximab soravtansine and was reversible with topical steroids. A bilateral medium-vessel choroidal vasculopathy with serous retinal detachment was seen with ipilimumab. The most frequent medication with ocular toxicity was interferon-α(2b) (IFN-α(2b)) (6/31, 19.4%); headache was typical in these patients (83.3%). Ibrutinib ocular toxicity was second most common (5/31, 16.1%), usually causing red or dry eye, while one patient developed branch retinal artery occlusion. Retinal abnormalities documented on OCT imaging occurred with IFN-α(2b), ipilimumab, binimetinib, and docetaxel, while rod-cone ERG abnormality was seen with cisplatin. Inflammatory conditions included anterior scleritis with zoledronic acid, focal eyelid inflammation with veliparib, bilateral chemosis with R-CHOP, iritis, and blepharospasm with IFN-α(2b). AION occurred with pemetrexed, and transient vision loss with hyperemic disc OS was seen with FOLFOX. Two patients (2/31, 6.5%) developed permanent vision loss. Six patients were lost to follow-up, and the clinical course was unknown (6/31, 19.4%). Cases of permanent visual loss were observed; yet, in the majority of side effects, they improved with topical therapy and/or holding the medication. Further research is needed to elucidate the incidence and the pathophysiology of these side effects and maximize patient quality of life.

Precision public health to inhibit the contagion of disease and move toward a future in which microbes spread health

Antimicrobial resistance continues to outpace the development of new chemotherapeutics. Novel pathogens continue to evolve and emerge. Public health innovation has the potential to open a new front in the war of “our wits against their genes” (Joshua Lederberg). Dense sampling coupled to next generation sequencing can increase the spatial and temporal resolution of microbial characterization while sensor technologies precisely map physical parameters relevant to microbial survival and spread. Microbial, physical, and epidemiological big data could be combined to improve prospective risk identification. However, applied in the wrong way, these approaches may not realize their maximum potential benefits and could even do harm. Minimizing microbial-human interactions would be a mistake. There is evidence that microbes previously thought of at best “benign” may actually enhance human health. Benign and health-promoting microbiomes may, or may not, spread via mechanisms similar to pathogens. Infectious vaccines are approaching readiness to make enhanced contributions to herd immunity. The rigorously defined nature of infectious vaccines contrasts with indigenous “benign or health-promoting microbiomes” but they may converge. A “microbial Neolithic revolution” is a possible future in which human microbial-associations are understood and managed analogously to the macro-agriculture of plants and animals. Tradeoffs need to be framed in order to understand health-promoting potentials of benign, and/or health-promoting microbiomes and infectious vaccines while also discouraging pathogens. Super-spreaders are currently defined as individuals who play an outsized role in the contagion of infectious disease. A key unanswered question is whether the super-spreader concept may apply similarly to health-promoting microbes. The complex interactions of individual rights, community health, pathogen contagion, the spread of benign, and of health-promoting microbiomes including infectious vaccines require study. Advancing the detailed understanding of heterogeneity in microbial spread is very likely to yield important insights relevant to public health.

New hydrazides derivatives of isoniazid against Mycobacterium tuberculosis: Higher potency and lower hepatocytotoxicity

Tuberculosis (TB) is one of the leading causes of death worldwide. The emergence of multi-drug resistant strains of Mycobacterium tuberculosis (Mtb) and TB-HIV co-infection are major public health challenges. The anti-TB drugs of first choice were developed more than 4 decades ago and present several adverse effects, making the treatment of TB even more complicated and the development of new chemotherapeutics for this disease imperative. In this work, we synthesized two series of new acylhydrazides and evaluated their activity against different strains of Mtb. Derivatives of isoniazid (INH) showed important anti-Mtb activity, some being more potent than all anti-TB drugs of first choice. Moreover, three compounds proved to be more potent than INH against resistant Mtb. The Ames test showed favorable results for two of these substances compared to INH, one of which presented expressly lower toxicity to HepG2 cells than that of INH. This result shows that this compound has the potential to overcome one of the main adverse effects of this drug.

ITRAQ Quantitative Proteomic Profiling and MALDI-MSI of Colon Cancer Spheroids Treated with Combination Chemotherapies in a 3D Printed Fluidic Device.

For a patient with metastatic colorectal cancer there are limited clinical options aside from chemotherapy. Unfortunately, the development of new chemotherapeutics is a long and costly process. New methods are needed to identify promising drug candidates earlier in the drug development process. Most chemotherapies are administered to patients in combinations. Here, an in vitro platform is used to assess the penetration and metabolism of combination chemotherapies in three-dimensional colon cancer cell cultures, or spheroids. Colon carcinoma HCT 116 cells were cultured and grown into three-dimensional cell culture spheroids. These spheroids were then dosed with a common combination chemotherapy, FOLFIRI (folinic acid, 5-fluorouracil, and irinotecan) in a 3D printed fluidic device. This fluidic device allows for the dynamic treatment of spheroids across a semipermeable membrane. Following dosing, the spheroids were harvested for quantitative proteomic profiling to examine the effects of the combination chemotherapy on the colon cancer cells. Spheroids were also imaged to assess the spatial distribution of administered chemotherapeutics and metabolites with MALDI-imaging mass spectrometry. Following treatment, we observed penetration of folinic acid to the core of spheroids and metabolism of the drug in the outer proliferating region of the spheroid. Proteomic changes identified included an enrichment of several cancer-associated pathways. This innovative dosing device, along with the proteomic evaluation with iTRAQ-MS/MS, provides a robust platform that could have a transformative impact on the preclinical evaluation of drug candidates. This system is a high-throughput and cost-effective approach to examine novel drugs and drug combinations prior to animal testing.

The Economics of Personalized Therapy in Metastatic Colorectal Cancer

Though the prognosis for patients with advanced colorectal cancer has improved significantly over the past two decades due to the development of new chemotherapeutics and biologic agents, this progress has come at an increased cost to patients and to the healthcare system. The cost of cancer care in the USA is rising at an alarming rate and far in excess of spending in other developed countries. The identification of predictive biomarkers that can help clinicians target existing and future therapies to patients who are most likely to benefit (and away from patients who would not benefit) has the potential to improve the value of cancer therapy and direct healthcare resources more efficiently. Here, we review established and emerging predictive biomarkers in colorectal cancer treatment and the cost implications of utilizing these markers in clinical practice.

Mechanisms associated to cytotoxicity and antimicrobial activities of VLC fractions isolated from brown seaweed Fucus spiralis

Mechanisms associated to cytotoxicity and antimicrobial activities of VLC fractions isolated from brown seaweed Fucus spiralis

Compound library screening identified Akt/PKB kinase pathway inhibitors as potential key molecules for the development of new chemotherapeutics against schistosomiasis

Protein kinases (PKs) are one of the largest protein families in most eukaryotic organisms. These enzymes are involved in the control of cell proliferation, differentiation and metabolism and a large number of the anticancer drugs currently used are directed against PKs. The structure and function of PKs are well conserved throughout evolution. In schistosome parasites, PKs were shown to be involved in essential functions at every stage of the parasite life cycle, making these enzymes promising anti-parasite drug targets. In this study, we tested a panel of commercial inhibitors for various PKs and analyzed their effects on pairing and egg production by schistosomes as well as their toxicity towards schistosomula larvae. Results obtained confirmed the deleterious effect of PK targeting on Schistosoma mansoni physiology and the important function of different tyrosine and serine/threonine kinases in the biology and reproduction of this parasite. They also indicated for the first time that the Protein kinase B (also called Akt) which is a major downstream target of many receptor tyrosine kinases and a central player at the crossroads of signal transduction pathways activated in response to growth factors and insulin, can constitute a novel target for anti-schistosome chemotherapy. Structural and functional studies have shown that SmAkt is a conserved kinase and that its activity can be inhibited by commercially available Akt inhibitors. In treated adult worms, Akt/PKB kinase pathway inhibitors induced profound alterations in pairing and egg laying and they also greatly affected the viability of schistosomula larvae.

Transcriptome Analysis of Encystation in Entamoeba invadens

Encystation is an essential differentiation process for the completion of the life cycle of a group of intestinal protozoa including Entamoeba histolytica, the causative agent of intestinal and extraintestinal amebiasis. However, regulation of gene expression during encystation is poorly understood. To comprehensively understand the process at the molecular level, the transcriptomic profiles of E . invadens , which is a related reptilian species that causes an invasive disease similar to that of E. histolytica, was investigated during encystation. Using a custom-generated Affymetrix platform microarray, we performed time course (0.5, 2, 8, 24, 48, and 120 h) gene expression analysis of encysting E . invadens . ANOVA analysis revealed that a total of 1,528 genes showed ≥3 fold up-regulation at one or more time points, relative to the trophozoite stage. Of these modulated genes, 8% (116 genes) were up-regulated at the early time points (0.5, 2 and 8h), while 63% (962 genes) were up-regulated at the later time points (24, 48, and 120 h). Twenty nine percent (450 genes) are either up-regulated at 2 to 5 time points or constitutively up-regulated in both early and late stages. Among the up-regulated genes are the genes encoding transporters, cytoskeletal proteins, proteins involved in vesicular trafficking (small GTPases), Myb transcription factors, cysteine proteases, components of the proteasome, and enzymes for chitin biosynthesis. This study represents the first kinetic analysis of gene expression during differentiation from the invasive trophozoite to the dormant, infective cyst stage in Entamoeba . Functional analysis on individual genes and their encoded products that are modulated during encystation may lead to the discovery of targets for the development of new chemotherapeutics that interfere with stage conversion of the parasite.

Abstract 955: CT45A6, cancer/testis antigen 45 family member, confer drug resistance to lung cancer cell lines.

Abstract Lung cancer is the leading cause of cancer related death in the world. Although recent advances in development of new chemotherapeutics offer a great promise to clinical outcome, drug resistance is still major concern of clinician. Cisplatin is platinum based drug that variously, combined with many other chemotherapeutics, have been widely used in the treatment of cancer. However, tumors usually become resistant to cisplatin during treatment. We performed RNA sequencing with 7 lung cancer cell lines and selected candidate genes to identify novel drug-resistance genes. RNA sequence analysis showed that one of these genes contained CT45A6. CT45A6 is a member of CT45 family. CT45 is a cancer/testis antigen family 45 that is located in Xq26.3 and expressed normally in testis and various cancers including lung cancer. However, little is known about its biological function, especially about drug resistance. Here, we show that CT45A6 confers cisplatin resistance into lung cancer cell lines. CT45A6 gene is significantly over-expressed in A549PR (cisplatin-resistant A549 lung cancer cell line) compared with wild type A549 lung cancer cell line. Interestingly, overexpression of CT45A6 in CT45A6-low NCI-H2009 and NCI-H358 lung cancer cell lines showed increased resistance to cisplatin and G2 phase population. Inversely, knockdown of CT45A6 in A549PR cells significantly decreased cisplatin-resistance. Thus, our findings indicate that CT45A6 may be a potential target to overcome drug resistance. Citation Format: Shin-Tae Kim, Seong-Jin Kim. CT45A6, cancer/testis antigen 45 family member, confer drug resistance to lung cancer cell lines. [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 955. doi:10.1158/1538-7445.AM2013-955