Melanoma prevention using topical PBISe

Polyfunctionalized organoselenides: New synthetic approach from selenium-containing cyanohydrins and anti-melanoma activity

A series of seleno-containing polyfunctionalized compounds was synthesized exploring cyanohydrin chemistry, including α-hydroxy esters, α-hydroxy acids, 1,2-diols, and 1,2-diacetates, with yields ranging from 26 up to 99 %. The cytotoxicity of all synthesized compounds was then evaluated using a non-tumor cell line (BALB/3T3 murine fibroblasts), and those deemed non-cytotoxic had their anti-melanoma activity evaluated using B16-F10 murine melanoma cells. These assays identified two compounds with selective cytotoxic activity against the tested melanoma cell line, showing a potential anti-melanoma application.

Regulation of Tyrosinase Enzyme Activity by Glutathione Peroxidase Mimics

Hydrogen peroxide plays a crucial role in the melanogenesis process by regulating the activity of the key melanin-forming enzyme tyrosinase, responsible for the browning of fruits, vegetables, and seafood. Therefore, a molecule with dual activities, both efficient tyrosinase inhibition and strong hydrogen peroxide degrading ability, may act as a promising antibrowning agent. Herein, we report highly efficient selone-based mushroom tyrosinase inhibitors 2 and 3 with remarkable glutathione peroxidase (GPx) enzyme-like activity. The presence of benzimidazole moiety enhances the tyrosinase inhibition efficiency of selone 2 (IC₅₀ = 0.4 μM) by almost 600 times higher than imidazole-based selone 1 (IC₅₀ = 238 μM). Interestingly, the addition of another aromatic ring to the benzimidazole moiety has led to the development of an efficient lipid-soluble tyrosinase inhibitor 3 (IC₅₀ = 2.4 μM). The selenium center and the -NH group of 2 and 3 are extremely crucial to exhibit high GPx-like activity and tyrosinase inhibition potency. The hydrophobic moiety of the inhibitors (2 and 3) further assists them in tightly binding at the active site of the enzyme and facilitates the C═Se group to strongly coordinate with the copper ions. Inhibitor 2 exhibited excellent antibrowning and polyphenol oxidase inhibition properties in banana and apple juice extracts.

Novel Aurora A and Protein Kinase C (α, β1, β2, and θ) Multitarget Inhibitors: Impact of Selenium Atoms on the Potency and Selectivity

Aurora kinases and protein kinase C (PKC) have been shown to be involved in different aspects of cancer progression. To date, no dual Aurora/PKC inhibitor with clinical efficacy and low toxicity is available. Here, we report the identification of compound 2e as a potent small molecule capable of selectively inhibiting Aurora A kinase and PKC isoforms α, β1, β2 and θ. Compound 2e demonstrated significant inhibition of the colony forming ability of metastatic breast cancer cells in vitro and metastasis development in vivo. In vitro kinase screening and molecular modeling studies revealed the critical role of the selenium-containing side chains within 2e, where selenium atoms were shown to significantly improve its selectivity and potency by forming additional interactions and modulating the protein dynamics. In comparison to other H-bonding heteroatoms such as sulfur, our studies suggested that these selenium atoms also confer more favorable PK properties.

Indole derivatives as tubulin polymerization inhibitors for the development of promising anticancer agents

The α- and β-tubulins are the major polypeptide components of microtubules (MTs), which are attractive targets for anticancer drug development. Indole derivatives display a variety of biological activities including antitumor activity. In recent years, a great number of indole derivatives as tubulin polymerization inhibitors have sprung up, which encourages medicinal chemists to pursue promising inhibitors with improved antitumor activities, excellent physicochemical, pharmacokinetic and pharmacodynamic properties. In this review, the recent progress from 2010 to present in the development of indole derivatives as tubulin polymerization inhibitors was summarized and reviewed, which would provide useful clues and inspirations for further design of outstanding tubulin polymerization inhibitors.

Design, synthesis and biological evaluation of vinyl selenone derivatives as novel microtubule polymerization inhibitors

A series of novel vinyl selenone derivatives were designed, synthesized and evaluated as the tubulin polymerization inhibitors using a bioisosteric strategy. Among them, the representative compound 11k exhibited satisfactory anti-proliferative activities with IC₅₀ values ranging from 0.287 to 0.621 μM against a panel of cancer cell lines. Importantly, 11k displayed more potent in vivo antitumor activity than the positive control paclitaxel, CA-4 and parent compound 4 without apparent toxicity, which was presumably ascribed to the antiangiogenic, antiproliferative and selective effects of selenium, along with the unique physiological activity of indole skeleton, which were both introduced into the structure of target compounds. Further mechanism study demonstrated that compound 11k showed potent activity in tubulin polymerization inhibition with IC₅₀ value of 1.82 μM. Moreover, cellular mechanism studies disclosed that 11k blocked cell cycle arrest at G2/M phase, induced cell apoptosis and depolarized mitochondria of K562 cells. Meanwhile, 11k reduced the cell migration and had potent vascular disrupting activity. In summary, 11k could serve as a promising lead for the development of more efficient microtubule polymerization inhibitors for cancer therapy.

Role and Therapeutic Targeting of the PI3K/Akt/mTOR Signaling Pathway in Skin Cancer: A Review of Current Status and Future Trends on Natural and Synthetic Agents Therapy

The mammalian or mechanistic target of rapamycin (mTOR) and associated phosphatidyl-inositiol 3-kinase (PI3K)/protein kinase B (Akt) pathways regulate cell growth, differentiation, migration, and survival, as well as angiogenesis and metabolism. Dysregulation of these pathways is frequently associated with genetic/epigenetic alterations and predicts poor treatment outcomes in a variety of human cancers including cutaneous malignancies like melanoma and non-melanoma skin cancers. Recently, the enhanced understanding of the molecular and genetic basis of skin dysfunction in patients with skin cancers has provided a strong basis for the development of novel therapeutic strategies for these obdurate groups of skin cancers. This review summarizes recent advances in the roles of PI3K/Akt/mTOR and their targets in the development and progression of a broad spectrum of cutaneous cancers and discusses the current progress in preclinical and clinical studies for the development of PI3K/Akt/mTOR targeted therapies with nutraceuticals and synthetic small molecule inhibitors.

Identification of a Novel Quinoxaline-Isoselenourea Targeting the STAT3 Pathway as a Potential Melanoma Therapeutic

The prognosis for patients with metastatic melanoma remains very poor. Constitutive signal transducer and activator of transcription 3 (STAT3) activation has been correlated to metastasis, poor patient survival, larger tumor size, and acquired resistance against vemurafenib (PLX-4032), suggesting its potential as a molecular target. We recently designed a series of isoseleno- and isothio-urea derivatives of several biologically active heterocyclic scaffolds. The cytotoxic effects of lead isoseleno- and isothio-urea derivatives (compounds 1 and 3) were studied in a panel of five melanoma cell lines, including B-RAF^V600E-mutant and wild-type (WT) cells. Compound 1 (IC₅₀ range 0.8–3.8 µM) showed lower IC₅₀ values than compound 3 (IC₅₀ range 8.1–38.7 µM) and the mutant B-RAF specific inhibitor PLX-4032 (IC₅₀ ranging from 0.4 to >50 µM), especially at a short treatment time (24 h). These effects were long-lasting, since melanoma cells did not recover their proliferative potential after 14 days of treatment. In addition, we confirmed that compound 1 induced cell death by apoptosis using Live-and-Dead, Annexin V, and Caspase3/7 apoptosis assays. Furthermore, compound 1 reduced the protein levels of STAT3 and its phosphorylation, as well as decreased the expression of STAT3-regulated genes involved in metastasis and survival, such as survivin and c-myc. Compound 1 also upregulated the cell cycle inhibitor p21. Docking studies further revealed the favorable binding of compound 1 with the SH2 domain of STAT3, suggesting it acts through STAT3 inhibition. Taken together, our results suggest that compound 1 induces apoptosis by means of the inhibition of the STAT3 pathway, non-specifically targeting both B-RAF-mutant and WT melanoma cells, with much higher cytotoxicity than the current therapeutic drug PLX-4032.

The design, synthesis and evaluation of selenium-containing 4-anilinoquinazoline hybrids as anticancer agents and a study of their mechanism

We report the design, synthesis and evaluation of 2-chloro-N-methyl-N-(4-selenocyanatophenyl)quinazolin-4-amine and its analogues as anticancer agents and the mechanism study.

5-Selenocyanatouracil: A Potential Hypoxic Radiosensitizer. Electron Attachment Induced Formation of Selenium Centered Radical

The propensity of 5-selenocyanatouracil (SeCNU) to decomposition induced by attachment of electron was scrutinized with the G3B3 composite quantum-chemical method and radiolytic studies. Favorable thermodynamic (Gibbs free reaction energy of -13.65 kcal/mol) and kinetic (Gibbs free activation energy of 1.22 kcal/mol) characteristics revealed by the G3B3 free energy profile suggest SeCNU to be sensitive to electron attachment. The title compound was synthesized in the reaction between uracil and selenocyanogen chloride in acetic acid. Then, an aqueous and deoxygenated solution of the HPLC purified compound containing tert-butanol as a hydroxyl radical scavenger was irradiated with X-rays. SeCNU radio-degradation results in two major products: the U-Se-Se-U dimer and the adduct of the ^●OtBu radical to the U-Se^● radical, U-Se-OtBu. The effects of radiolysis as well as the results of G3B3 calculations point to U-Se^● as the primary product of dissociative electron attachment to SeCNU. The MTT test shows that SeCNU is nontoxic in vitro in concentrations equal to or lower than 10^-6 M. Ionizing radiation will probably induce cytotoxic intra- and interstrand DNA cross-links as well as protein-DNA cross-links in the genomic DNA labeled with SeCNU.

Synthesis and evaluation of selenium-containing indole chalcone and diarylketone derivatives as tubulin polymerization inhibition agents

Sixteen new selenium-containing indole chalcone and diarylketone derivatives were synthesized and evaluated as tubulin polymerization inhibitors. Compound 25b exhibited the most potent antiproliferative activities and effectively inhibited tubulin polymerization (IC₅₀ = 2.1 ± 0.27 μM).

A Selenium Containing Inhibitor for the Treatment of Hepatocellular Cancer

Hepatocellular carcinoma (HCC) is the third most deadly cancer in the world. New treatment strategies are desperately needed due to limited standard therapies. Activation of the Erk, Akt, and STAT3pathways is implicated in the prognosis of HCC. The Se,Se'-1,4-phenylenebis(1,2-ethanediyl) bisisoselenourea (PBISe), is a selenium-containing MAPK and PI3 kinase inhibitor, effectively inhibit tumorigenesis in a variety of experimental models. The aim of our study is to demonstrate the potential role of PBISe in the treatment of HCC. The anti-proliferative and pro-apoptotic ability of PBISe is studied in vitro in four human HCC cell lines and in vivo in a spontaneous murine HCC model. Inhibition of cancer growth was performed by cell viability assay and apoptosis by caspase 3/7, PARP cleavage, annexin-V, and TUNEL assays. Role of PBISe on PI3 kinase, MAPK and STAT3 signaling is determined by Western blotting. In vivo effects of PBISe on tumor sizes were monitored using MRI in a spontaneous murine HCC. Liver tissues from the PBISe-treated mice are analyzed for angiogenesis, proliferation, and signaling pathway markers. Overall, PBISe activated caspase-3/7 and increased DNA fragmentation, which is positively correlated with the increased PARP cleavage. PBISe promoted apoptosis by inhibiting PI3K, MAPK, and STAT3 signaling with significant reduction in the tumor sizes (p < 0.007). PBISe-treated tumors reduced survival marker PCNA, and angiogenesis markers Vegf-A, Vegf-R3 and CD34. These results demonstrate the chemotherapeutic effects of PBISe, by inhibiting tumor growth and facilitating tumor apoptosis for HCC treatment.

Design, Synthesis, and Biological Evaluation of Novel Selenium (Se-NSAID) Molecules as Anticancer Agents

The synthesis and anticancer evaluation of novel selenium-nonsteroidal anti-inflammatory drug (Se-NSAID) hybrid molecules are reported. The Se-aspirin analogue 8 was identified as the most effective agent in reducing the viability of different cancer cell lines, particularly colorectal cancer (CRC) cells, was more selective toward cancer cells than normal cells, and was >10 times more potent than 5-FU, the current therapy for CRC. Compound 8 inhibits CRC growth via the inhibition of the cell cycle in G1 and G2/M phases and reduces the cell cycle markers like cyclin E1 and B1 in a dose dependent manner; the inhibition of the cell cycle may be dependent on the ability of 8 to induce p21 expression. Furthermore, 8 induces apoptosis by activating caspase 3/7 and PARP cleavage, and its longer exposure causes increase in intracellular ROS levels in CRC cells. Taken together, 8 has the potential to be developed further as a chemotherapeutic agent for CRC.

Modular Three-component Delivery System Facilitates HLA Class I Antigen Presentation and CD8(+) T-cell Activation Against Tumors

Cell-mediated immunotherapies have potential as stand-alone and adjuvant therapies for cancer. However, most current protocols suffer from one or more of three major issues: cost, safety, or efficacy. Here we present a nanoparticle delivery system that facilitates presentation of an immunogenic measles antigen specifically in cancer cells. The delivery system does not contain viral particles, toxins, or biologically derived material. Treatment with this system facilitates activation of a secondary immune response against cancer cells, bypassing the need to identify tumor-associated antigens or educate the immune system through a primary immune response. The delivery system consists of a stealth liposome displaying a cancer-specific targeting peptide, named H1299.3, on its exterior surface and encapsulating H250, an immunogenic human leukocyte antigen class 1 restricted peptide. This targeted-nanoparticle facilitates presentation of the H250 peptide in major histocompatibility complex class I molecules. Activation is dependent on the targeting peptide, previous antigen exposure, and utilizes a novel autophagy-mediated mechanism to facilitate presentation. Treatment with this liposome results in a significant reduction of tumor growth using an aggressive LLC1 model in vaccinated C57BL/6 mice. These data provide proof-of-principle for a novel cell-mediated immunotherapy that is scalable, contains no biologically derived material, and is an efficacious cancer therapy.

Identification of a novel lysosomal trafficking peptide using phage display biopanning coupled with endocytic selection pressure

Methods to select ligands that accumulate specifically in cancer cells and traffic through a defined endocytic pathway may facilitate rapid pairing of ligands with linkers suitable for drug conjugate therapies. We performed phage display biopanning on cancer cells that are treated with selective inhibitors of a given mechanism of endocytosis. Using chlorpromazine to inhibit clathrin-mediated endocytosis in H1299 nonsmall cell lung cancer cells, we identified two clones, ATEPRKQYATPRVFWTDAPG (15.1) and a novel peptide LQWRRDDNVHNFGVWARYRL (H1299.3). The peptides segregate by mechanism of endocytosis and subsequent location of subcellular accumulation. The H1299.3 peptide primarily utilizes clathrin-mediated endocytosis and colocalizes with Lamp1, a lysosomal marker. Conversely, the 15.1 peptide is clathrin-independent and localizes to a perinuclear region. Thus, this novel phage display scheme allows for selection of peptides that selectively internalize into cells via a known mechanism of endocytosis. These types of selections may allow for better matching of linker with targeting ligand by selecting ligands that internalize and traffic to known subcellular locations.

Targeting nitric oxide signaling with nNOS inhibitors as a novel strategy for the therapy and prevention of human melanoma

AIMS

Our previous studies have shown that nitric oxide (NO) plays an important role in increasing the invasion and proliferation of human melanoma cells, suggesting that targeting NO signaling may facilitate therapy and prevention. Neuronal nitric oxide synthase (nNOS) is present in melanocytes, a cell type that originates from the neural crest. The aims of this study were to determine the role of nNOS in melanoma progression and the potential antitumor effects of novel synthesized nNOS inhibitors.

RESULTS

In vitro studies demonstrated abundant expression of nNOS in melanoma compared to melanocytes, which was inducible by ultraviolet radiation and was associated with increased NO generation. nNOS was also detected in melanoma biopsies that increased with disease stage. Knockdown of nNOS in melanoma cells diminished L-arginine-induced NO production; the metastatic capacity was also reduced as well as the levels of MMP-1, Bcl-2, JunD, and APE/Ref-1. Similar inhibition of NO and invasion potential was observed utilizing novel, highly selective nNOS inhibitors. In three-dimensional human skin reconstructs, the nNOS inhibitor cpd8 effectively reversed the melanoma overgrowth stimulated by NO stress.

INNOVATION

Our work lays the foundation for development of clinical "drug-like" nNOS inhibitors as a new and promising strategy for the chemoprevention of early melanoma progression and the inhibition of secondary melanoma in high-risk individuals.

CONCLUSION

Based on our observations, we propose that nNOS in melanoma results in constitutive overproduction of NO, which stimulates proliferation and increases invasion potential, leading to subsequent development of metastases.

Post SELECT: selenium on trial

Selenium is an essential trace element for humans and other animals that is required in very small amounts for proper growth and functioning. Several selenium compounds have shown promise as cancer chemopreventive and chemotherapeutic agents. However, the negative outcome of the SELECT trial to some extent dampened the enthusiasm of selenium-related drug development. A look at the selenium compounds, their diverse mechanism of action, bioavailability and efficacy based on chemical structure, however, suggests that failure of SELECT that used selenomethionine supplement to prevent prostate cancer was not a failure of selenium compounds as a whole. This is certainly true in regard to therapeutic applications of selenium compounds. This article puts these arguments in perspective, and based on the literature reports, especially several newly developed selenium compounds, emphasizes the importance of selenium in the development of chemopreventive and particularly chemotherapeutic drugs for cancer in near future.

Current and future trials of targeted therapies in cutaneous melanoma

In order to effectively treat melanoma, targeted inhibition of key m-echanistic events regulating melanoma development such as cell proliferation, survival, angiogenesis and invasion or metastasis needs to be accomplished. The Mitogen Activated Protein Kinase (MAPK) pathway has been identified as a key player in melanoma development making this cascade an important therapeutic target. However, identification of the ideal pathway member to therapeutically target for maximal clinical benefit remains a challenge. In normal cells, the MAPK pathway relays extracellular signals from the cell membrane to the nucleus via a cascade of phosphorylation events, which promote cancer development. Dysregulation of the MAPK pathway occurs frequently in many human cancers including melanoma. Mutations in the B-RAF and RAS genes, genetic or epigenetic modifications are the key aberrations observed in this signaling cascade. Constitutive activation of this pathway causes oncogenic transformation of cells by promoting cell proliferation, invasion, metastasis, migration, survival and angiogenesis. This review provides an overview of (a) key members of MAPK signaling regulating melanoma development; (b) key proteins which can serve as biomarkers to assess disease progression; (c) the clinical efficacy of various pharmacological agents targeting MAPK pathway; (d) current clinical trials evaluating downstream targets of the MAPK pathway; (e) issues associated with pharmacological agents such as drug resistance, induction of cancers; and finally (e) various strategies overcoming drug resistance.

Selenium compounds, apoptosis and other types of cell death: an overview for cancer therapy

Selenium (Se) is an essential trace element involved in different physiological functions of the human body and plays a role in cancer prevention and treatment. Induction of apoptosis is considered an important cellular event that can account for the cancer preventive effects of Se. The mechanisms of Se-induced apoptosis are associated with the chemical forms of Se and their metabolism as well as the type of cancer studied. So, some selenocompounds, such as SeO₂ involve the activation of caspase-3 while sodium selenite induces apoptosis in the absence of the activation of caspases. Modulation of mitochondrial functions has been reported to play a key role in the regulation of apoptosis and also to be one of the targets of Se compounds. Other mechanisms for apoptosis induction are the modulation of glutathione and reactive oxygen species levels, which may function as intracellular messengers to regulate signaling pathways, or the regulation of kinase, among others. Emerging evidence indicates the overlaps between the apoptosis and other types of cell death such as autophagy. In this review we report different processes of cell death induced by Se compounds in cancer treatment and prevention.

Selenium-containing histone deacetylase inhibitors for melanoma management

Melanoma incidence and mortality rates continue to increase each year. Lack of clinically viable agents, drug combinations, effective targeted delivery approaches and success inhibiting targets in tumor tissue have made this disease one of the most difficult to treat, which makes prevention an important option for decreasing disease incidence and mortality rates. Inhibiting histone deacetylases (HDAC) is an approach currently being explored to more effectively treat melanoma but use for prevention has not been explored. In this study, novel selenium containing derivatives of the FDA approved HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) called 5-phenylcarbamoylpentyl selenocyanide (PCP-SeCN) and Bis{5-phenylcarbamoylpentyl} diselenide (B(PCP)-2Se) were created and efficacy tested for preventing early melanocytic lesion development in skin. Topical application of PCP-SeCN and B(PCP)-2Se inhibited melanocytic lesion development in laboratory-generated skin by up to 87% with negligible toxicological effect. Mechanistically, PCP-SeCN and B(PCP)-2Se inhibited HDAC activity and had new inhibitory properties by moderating Akt activity to induce cellular apoptosis as demonstrated by an increase in the sub-G₀-G₁ cell population, and cleaved caspase-3 as well as PARP levels. Furthermore, PCP-SeCN and B(PCP)-2Se inhibited cell proliferation by inhibiting cyclin D1 expression and increasing p21 levels. Thus, PCP-SeCN and B(PCP)-2Se are potential melanoma chemopreventive agents with enhanced efficacy compared with SAHA due to new PI3 kinase pathway inhibitory properties.

Chemoprevention of melanoma

Despite advances in drug discovery programs and molecular approaches for identifying drug targets, incidence and mortality rates due to melanoma continue to rise at an alarming rate. Existing preventive strategies generally involve mole screening followed by surgical removal of the benign nevi and abnormal moles. However, due to lack of effective programs for screening and disease recurrence after surgical resection, there is a need for better chemopreventive agents. Although sunscreens have been used extensively for protecting from UV-induced melanomas, results of correlative population-based studies are controversial, with certain studies suggest increased skin cancer risk in sunscreen users. Therefore, these studies require further authentication to conclusively confirm the chemoprotective efficacy of sunscreens. This chapter reviews the current understanding regarding melanoma chemoprevention and the various strategies used to accomplish this objective.

The Akt signaling pathway: an emerging therapeutic target in malignant melanoma

Studies using cultured melanoma cells and patient tumor biopsies have demonstrated deregulated PI3 kinase-Akt3 pathway activity in ~70% of melanomas. Furthermore, targeting Akt3 and downstream PRAS40 has been shown to inhibit melanoma tumor development in mice. Although these preclinical studies and several other reports using small interfering RNAs and pharmacological agents targeting key members of this pathway have been shown to retard melanoma development, analysis of early Phase I and Phase II clinical trials using pharmacological agents to target this pathway demonstrate the need for (1) selection of patients whose tumors have PI3 kinase-Akt pathway deregulation, (2) further optimization of therapeutic agents for increased potency and reduced toxicity, (3) the identification of additional targets in the same pathway or in other signaling cascades that synergistically inhibit the growth and progression of melanoma, and (4) better methods for targeted delivery of pharmaceutical agents inhibiting this pathway. In this review we discuss key potential targets in PI3K-Akt3 signaling, the status of pharmacological agents targeting these proteins, drugs under clinical development, and strategies to improve the efficacy of therapeutic agents targeting this pathway.

Novel library of selenocompounds as kinase modulators

Although the causes of cancer lie in mutations or epigenic changes at the genetic level, their molecular manifestation is the dysfunction of biochemical pathways at the protein level. The 518 protein kinases encoded by the human genome play a central role in various diseases, a fact that has encouraged extensive investigations on their biological function and three dimensional structures. Selenium (Se) is an important nutritional trace element involved in different physiological functions with antioxidative, antitumoral and chemopreventive properties. The mechanisms of action for selenocompounds as anticancer agents are not fully understood, but kinase modulation seems to be a possible pathway. Various organosulfur compounds have shown antitumoral and kinase inhibition effects but, in many cases, the replacement of sulfur by selenium improves the antitumoral effect of compounds. Although Se atom possesses a larger atomic volume and nucleophilic character than sulfur, Se can also formed interactions with aminoacids of the catalytic centers of proteins. So, we propose a novel chemical library that includes organoselenium compounds as kinase modulators. In this study thirteen selenocompounds have been evaluated at a concentration of 3 or 10 µM in a 24 kinase panel using a Caliper LabChip 3000 Drug Discover Platform. Several receptor (EGFR, IGFR1, FGFR1…) and non-receptor (Abl) kinases have been selected, as well as serine/threonine/lipid kinases (AurA, Akt, CDKs, MAPKs…) implicated in main cancer pathways: cell cycle regulation, signal transduction, angiogenesis regulation among them. The obtained results showed that two compounds presented inhibition values higher than 50% in at least four kinases and seven derivatives selectively inhibited one or two kinases. Furthermore, three compounds selectively activated IGF-1R kinase with values ranging from −98% to −211%. In conclusion, we propose that the replacement of sulfur by selenium seems to be a potential and useful strategy in the search of novel chemical compound libraries against cancer as kinase modulators.