Transcriptomics analyses reveal the effects of Pentagamaboronon-0-ol on PI3K/Akt and cell cycle of HER2+ breast cancer cells.

Introduction: Monoclonal antibodies and targeted therapies against HER2+ breast cancer has improved overall and disease-free survival in patients; however, encountering drug resistance causes recurrence, necessitating the development of newer HER2-targeted medications. A curcumin analog PGB-0-ol showed most cytotoxicity against HCC1954 HER2+ breast cancer cells than against other subtypes of breast cancer cells. Objective: Here, we employed next-generation sequencing technology to elucidate the molecular mechanism underlying the effect of PGB-0-ol on HCC1954 HER2+ breast cancer cells. Methods: The molecular mechanism underlying the action of PGB-0-ol on HCC1954 HER2+ breast cancer cells was determined using next-generation sequencing technologies. Additional bioinformatics studies were performed, including gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, disease-gene, and drug-gene associations, network topology analysis (NTA), and gene set enrichment analysis (GSEA). Results: We detected 2,263 differentially expressed genes (DEGs) (1,459 upregulated and 804 downregulated) in the PGB-0-ol- and DMSO-treated HCC1954 cells. KEGG enrichment data revealed the control of phosphatidylinositol signaling system, and ErbB signaling following PGB-0-ol treatment. Gene ontology (GO) enrichment analysis demonstrated that these DEGs governed cell cycle, participated in the mitotic spindle and nuclear membrane, and controlled kinase activity at the molecular level. According to the NTA data for GO enrichment, GSEA data for KEGG, drug-gene and disease-gene, PGB-0-ol regulated PI3K/Akt signaling and cell cycle in breast cancer. Overall, our investigation revealed the transcriptomic profile of PGB-0-ol-treated HCC1954 breast cancer cells following PGB-0-ol therapy. Bioinformatics analyses showed that PI3K/Akt signaling and cell cycle was modulated. However, further studies are required to validate the findings of this study.

Dodecaborate-Encapsulated Extracellular Vesicles with Modification of Cell-Penetrating Peptides for Enhancing Macropinocytotic Cellular Uptake and Biological Activity in Boron Neutron Capture Therapy.

Boron neutron capture therapy (BNCT) is a radiation therapy for cancer. In BNCT, the internalization of boron-10 atoms by cancer cells induces cell death through the generation of α particles and recoiling lithium-7 nuclei when irradiated with low-energy thermal neutrons. In this study, we aimed to construct exosomes [extracellular vesicles (EVs)]-based drug delivery technology in BNCT. Because of their pharmaceutical advantages, such as controlled immune responses and effective usage of cell-to-cell communication, EVs are potential next-generation drug delivery carriers. In this study, we successfully developed polyhedral borane anion-encapsulated EVs with modification of hexadeca oligoarginine, which is a cell-penetrating peptide, on the EV membrane to induce the actin-dependent endocytosis pathway, macropinocytosis, which leads to efficient cellular uptake and remarkable cancer cell-killing BNCT activity. The simple and innovative technology of the EV-based delivery system with "cassette" modification of functional peptides will be applicable not only for BNCT but also for a wide variety of therapeutic methodologies.

Chemical structure of hydrolysates of cereulide and their time course profile.

Hydrolysates of an emetic toxin cereulide were found in the broth of Bacillus cereus. The ester cleaved depsipeptides of cereulide were synthesized using liquid phase fragment condensation method starting from commercially available amino acids. The chemical structure of hydrolysates was verified tetradepsipeptide l-O-Val-l-Val-D-O-Leu-d-Ala and dodecadepsipeptide (D-O-Leu-d-Ala-l-O-Val-l-Val)3 using LC-TOFMS. Quantitative analysis of cereulide in the broth revealed production of cereulide in the stationary phase and decomposition in the death phase. The increase in tetradepsipeptide continued after the stationary phase until decomposition occurred.

Cellular uptake evaluation of pentagamaboronon-0 (PGB-0) for boron neutron capture therapy (BNCT) against breast cancer cells.

Pentagamaboronon-0 (PGB-0), a curcumin analog compound, has been synthesized as a candidate of boron-carrier pharmaceutical (BCP) for boron neutron capture therapy (BNCT); however, this compound is poorly soluble in water. To improve its solubility, aqueous formulations of PGB-0 with a monosaccharide, fructose or sorbitol, were successfully synthesized, namely PGB-0-F and PGB-0-So, respectively. The cytotoxicity study showed that PGB-0-F and PGB-0-So exerted low cytotoxicity against MCF-7 and MDA-MB 231 breast cancer cells. The cellular uptake study using inductively coupled plasma optical emission spectrometry (ICP-OES) and DAHMI live-cell imaging indicated that these compounds were accumulated and distributed within the cytoplasm and cell nuclei. The cellular uptake mechanism was also evaluated to clarify the contribution of the glucose transporter, and the results demonstrated that these compounds entered through active transport into MCF-7 cells but through passive diffusion into MDA-MB 231 cells. In conclusion, the sugar formulations of PGB-0 only improved PGB-0 solubility but had no role in its cellular uptake.

Synthesis of the reported structure of homocereulide and its vacuolation assay.

Homocereulide, isolated from marine bacterium Bacillus cereus, is an analog of emetic toxin cereulide. There is no report on its structure determination and involvement in B. cereus-associated food poisoning. Homocereulide is a cyclic dodecadepsipeptide composed of l-O-Val-l-Val-d-O-Leu-d-Ala and l-O-allo-Ile-d-Val-d-O-Leu-d-Ala. Here, we synthesized homocereulide using liquid phase fragment condensation. The NMR spectrum of synthesized homocereulide confirmed the intended structure and LC-MS results were consistent with natural products. Morphological evaluation using HEp-2 cells showed higher toxicity with homocereulide (1.39 nM) than cereulide (3.95 nM). Though cereulide is the main component in broth culture, homocereulide is also likely involved in B. cereus-associated food poisoning.

Development and Elucidation of a Novel Fluorescent Boron-Sensor for the Analysis of Boronic Acid-Containing Compounds.

Novel boron-containing drugs have recently been suggested as a new class of pharmaceuticals. However, the majority of current boron-detection techniques require expensive facilities and/or tedious pretreatment methods. Thus, to develop a novel and convenient detection method for boron-based pharmaceuticals, imine-type boron-chelating-ligands were previously synthesized for use in a fluorescent sensor for boronic acid containing compounds. However, the fluorescence quantum yield of the imine-type sensor was particularly low, and the sensor was easily decomposed in aqueous media. Thus, in this paper, we report the development of a novel, convenient, and stable fluorescent boron-sensor based on O- and N-chelation (i.e., 2-(pyridine-2yl)phenol), and a corresponding method for the quantitative and qualitative detection of boronic acid-containing compounds using this commercially available sensor is presented.

Comparison of the pharmacokinetics between L-BPA and L-FBPA using the same administration dose and protocol: a validation study for the theranostic approach using [18F]-L-FBPA positron emission tomography in boron neutron capture therapy.

BACKGROUND: Boron neutron capture therapy (BNCT) is a cellular-level particle radiation therapy that combines the selective delivery of boron compounds to tumour tissue with neutron irradiation. L-p-Boronophenylalanine (L-BPA) is a boron compound now widely used in clinical situations. Determination of the boron distribution is required for successful BNCT prior to neutron irradiation. Thus, positron emission tomography with [18F]-L-FBPA, an 18F-labelled radiopharmaceutical analogue of L-BPA, was developed. However, several differences between L-BPA and [18F]-L-FBPA have been highlighted, including the different injection doses and administration protocols. The purpose of this study was to clarify the equivalence between L-BPA and [19F]-L-FBPA as alternatives to [18F]-L-FBPA. METHODS: SCC-VII was subcutaneously inoculated into the legs of C3H/He mice. The same dose of L-BPA or [19F]-L-FBPA was subcutaneously injected. The time courses of the boron concentrations in blood, tumour tissue, and normal tissue were compared between the groups. Next, we administered the therapeutic dose of L-BPA or the same dose of [19F]-L-FBPA by continuous infusion and compared the effects of the administration protocol on boron accumulation in tissues. RESULTS: There were no differences between L-BPA and [19F]-L-FBPA in the transition of boron concentrations in blood, tumour tissue, and normal tissue using the same administration protocol. However, the normal tissue to blood ratio of the boron concentrations in the continuous-infusion group was lower than that in the subcutaneous injection group. CONCLUSIONS: No difference was noted in the time course of the boron concentrations in tumour tissue and normal tissues between L-BPA and [19F]-L-FBPA. However, the administration protocol had effects on the normal tissue to blood ratio of the boron concentration. In estimating the BNCT dose in normal tissue by positron emission tomography (PET), we should consider the possible overestimation of the normal tissue to blood ratio of the boron concentrations derived from the values measured by PET on dose calculation.

Detection of boronic acid derivatives in cells using a fluorescent sensor.

The detection of boron-containing compounds requires very expensive facilities and/or tedious sample pretreatments. In an effort to develop a convenient detection method for boronic acid derivatives, boron chelating-ligands were synthesized for use as fluorescent sensors. In this paper, the synthesis and properties of fluorescent sensors for boronic acid derivatives are reported.

Synthesis and in vitro evaluation of thiododecaborated α, α- cycloalkylamino acids for the treatment of malignant brain tumors by boron neutron capture therapy.

Boron-neutron capture therapy (BNCT) is an attractive technique for cancer treatment. As such, α, α-cycloalkyl amino acids containing thiododecaborate ([B12H11](2-)-S-) units were designed and synthesized as novel boron delivery agents for BNCT. In the present study, new thiododecaborate α, α-cycloalkyl amino acids were synthesized, and biological evaluation of the boron compounds as boron carrier for BNCT was carried out.

Extracellular Vesicles Comprising Carborane Prepared by a Host Exchanging Reaction as a Boron Carrier for Boron Neutron Capture Therapy.

With their low immunogenicity and excellent deliverability, extracellular vesicles (EVs) are promising platforms for drug delivery systems. In this study, hydrophobic molecule loading techniques were developed via an exchange reaction based on supramolecular chemistry without using organic solvents that can induce EV disruption and harmful side effects. To demonstrate the availability of an exchanging reaction to prepare drug-loading EVs, hydrophobic boron cluster carborane (CB) was introduced to EVs (CB@EVs), which is expected as a boron agent for boron neutron capture therapy (BNCT). The exchange reaction enabled the encapsulation of CB to EVs without disrupting their structure and forming aggregates. Single-particle analysis revealed that an exchanging reaction can uniformly introduce cargo molecules to EVs, which is advantageous in formulating pharmaceuticals. The performance of CB@EVs as boron agents for BNCT was demonstrated in vitro and in vivo. Compared to L-BPA, a clinically available boron agent, and CB delivered with liposomes, CB@EV systems exhibited the highest BNCT activity in vitro due to their excellent deliverability of cargo molecules via an endocytosis-independent pathway. The system can deeply penetrate 3D cultured spheroids even in the presence of extracellular matrices. The EV-based system could efficiently accumulate in tumor tissues in tumor xenograft model mice with high selectivity, mainly via the enhanced permeation and retention effect, and the deliverability of cargo molecules to tumor tissues in vivo enhanced the therapeutic benefits of BNCT compared to the L-BPA/fructose complex. All of the features of EVs are also advantageous in establishing anticancer agent delivery platforms.

Tumour-suppressive effects of curcumin analogs CCA-1.1 and Pentagamavunone-1 in colon cancer: In vivo and in vitro studies.

This study aimed to evaluate the efficacy of Chemoprevention Curcumin Analog-1.1 (CCA-1.1) and Pentagamavunone-1 (PGV-1) in vivo and in vitro in colorectal cancer model. CCA-1.1 or PGV-1 was administered orally to 1,2-dimethylhydrazine (DMH)-induced rats for 16 weeks. The cytotoxicity of both compounds was tested on Caco-2, CT26, and NIH/3T3 cells using the MTT method. The cell cycle, apoptosis, and reactive oxygen species (ROS) levels were analyzed through flow cytometry. X-gal staining was used to examine the compound's effect on senescence. Oral co-administration of CCA-1.1 or PGV-1 significantly suppressed the carcinogenic characteristics and symptoms of premalignant colon cancer relative to DMH-only and untreated groups. CCA-1.1 and PGV-1 administration did not affect the blood profile. CCA-1.1 and PGV-1 demonstrated great cytotoxicity on Caco-2 and CT26 cells, with 50% inhibition concentration (IC50) values of 4.3 ± 0.2 and 3.1 ± 0.1 µM for CCA-1.1 and 11.2 ± 1.1 and 4.8 ± 0.1 µM for PGV-1, respectively, while not toxic against fibroblast cells. Both compounds instigated G2/M arrest and efficiently induced cell senescence and apoptosis. Moreover, these analogs selectively elevated oxidative stress in colon cancer cells without inducing noticeable changes in fibroblasts. In conclusion, PGV-1 and CCA-1.1 suppressed colorectal tumor formation and induced mitotic arrest.

The impact of TP53 status of tumor cells including the type and the concentration of administered 10B delivery agents on compound biological effectiveness in boron neutron capture therapy.

Human head and neck squamous cell carcinoma cells transfected with mutant TP53 (SAS/mp53) or neo vector (SAS/neo) were inoculated subcutaneously into left hind legs of nude mice. After the subcutaneous administration of a 10B-carrier, boronophenylalanine-10B (BPA) or sodium mercaptododecaborate-10B (BSH), at two separate concentrations, the 10B concentrations in tumors were measured using γ-ray spectrometry. The tumor-bearing mice received 5-bromo-2'-deoxyuridine (BrdU) continuously to label all intratumor proliferating (P) tumor cells, then were administered with BPA or BSH. Subsequently, the tumors were irradiated with reactor neutron beams during the time of which 10B concentrations were kept at levels similar to each other. Following irradiation, cells from some tumors were isolated and incubated with a cytokinesis blocker. The responses of BrdU-unlabeled quiescent (Q) and total (= P + Q) tumor cells were assessed based on the frequencies of micronucleation using immunofluorescence staining for BrdU. In both SAS/neo and SAS/mp53 tumors, the compound biological effectiveness (CBE) values were higher in Q cells and in the use of BPA than total cells and BSH, respectively. The higher the administered concentrations were, the smaller the CBE values became, with a clearer tendency in SAS/neo tumors and the use of BPA than in SAS/mp53 tumors and BSH, respectively. The values for BPA that delivers into solid tumors more dependently on uptake capacity of tumor cells than BSH became more alterable. Tumor micro-environmental heterogeneity might partially influence on the CBE value. The CBE value can be regarded as one of the indices showing the level of intratumor heterogeneity.

Multi-Targeted Neutron Capture Therapy Combined with an 18 kDa Translocator Protein-Targeted Boron Compound Is an Effective Strategy in a Rat Brain Tumor Model.

BACKGROUND: Boron neutron capture therapy (BNCT) has been adapted to high-grade gliomas (HG); however, some gliomas are refractory to BNCT using boronophenylalanine (BPA). In this study, the feasibility of BNCT targeting the 18 kDa translocator protein (TSPO) expressed in glioblastoma and surrounding environmental cells was investigated. METHODS: Three rat glioma cell lines, an F98 rat glioma bearing brain tumor model, DPA-BSTPG which is a boron-10 compound targeting TSPO, BPA, and sodium borocaptate (BSH) were used. TSPO expression was evaluated in the F98 rat glioma model. Boron uptake was assessed in three rat glioma cell lines and in the F98 rat glioma model. In vitro and in vivo neutron irradiation experiments were performed. RESULTS: DPA-BSTPG was efficiently taken up in vitro. The brain tumor has 16-fold higher TSPO expressions than its brain tissue. The compound biological effectiveness value of DPA-BSTPG was 8.43 to F98 rat glioma cells. The boron concentration in the tumor using DPA-BSTPG convection-enhanced delivery (CED) administration was approximately twice as high as using BPA intravenous administration. BNCT using DPA-BSTPG has significant efficacy over the untreated group. BNCT using a combination of BPA and DPA-BSTPG gained significantly longer survival times than using BPA alone. CONCLUSION: DPA-BSTPG in combination with BPA may provide the multi-targeted neutron capture therapy against HG.

Proline catalyzes direct C-H arylations of unactivated arenes.

Several amino acids were tested to catalyze the transition-metal-free direct C-H arylation of unactivated benzene derivatives. Among them, proline was found to be an excellent catalyst for the cross-coupling between aryl halides and unactivated arenes. The reaction presumably involves an aryl radical anion as the intermediate based on several experiments. The reaction using this catalyst system offers an option toward establishing an environmentally benign and cost-effective route to biaryls.

Copper-catalyzed synthesis of substituted indazoles from 2-chloroarenes at low catalyst-loading.

An efficient and convenient access to 1-substituted indazol-3-ones 2 has been achieved throughout the intramolecular C-N bond formations of 2-chloro-benzoic acid-N'-aryl and alkyl-hydrazides employing 0.5 mol% of cuprous (I) iodide and 20 mol% of L-proline as catalyst precursors under mild conditions in moderate to excellent yields.

Synthesis and cytotoxicity of the boron carrier pentagamaboronon-0-ol for boron neutron capture therapy against breast cancer.

Boronic acid-containing curcumin analog, pentagamaboronon-0 (PGB-0), acts as a potential boron-carrier agent but has limited water solubility. Thus, a new compound (PGB-0-ol) with better chemical and pharmacological properties than PGB-0 has been synthesized. Molecular docking was performed using a molecular operating environment. Prediction of PGB-0-ol absorption, distribution, metabolism, and excretion (ADME) was performed using pkCSM software. PGB-0-ol was synthesized by adding NaBH4 to PGB-0 and stirring for 1 h. The crude PGB-0-ol was purified using preparative layer chromatography. Cell viability was evaluated using the trypan blue exclusion assay. In comparison to PGB-0 based on molecular docking study, PGB-0-ol could interact in with several cancer biomarkers, such as human epidermal growth factor2 epidermal growth factor receptor, IκB kinase, folate receptor-α, and integrin αvß3. PGB-0-ol also showed an improved ADME profile because of its higher water solubility than PGB-0. PGB-0-ol was synthesized by selective ketone reduction of PGB-0 into primary alcohol by sodium borohydrate producing 30% yield. The cytotoxicity of PGB-0-ol against several breast cancer cells was lower than that of PGB-0. The novel compound PGB-0-ol was synthesized using simple steps. PGB-0-ol has low cytotoxicity against breast cancer cells and could be applied in boron neutron capture therapy as a boron carrier.

Dodecaborate Conjugates Targeting Tumor Cell Overexpressing Translocator Protein for Boron Neutron Capture Therapy.

We developed novel closo-dodecaborate ([B12H11]2-) anion-containing translocator protein (TSPO) ligand as a boron carrier for boron neutron capture therapy. This compound shows high water solubility and can deliver boron to TSPO highly expressed in breast cancer cells. We describe the synthesis and in vitro evaluation of a dodecaborate-based pyrazolopyrimidine.

The Evaluation of Cytotoxic Properties from CCB-2 Sugar Complexes Against TNBC and Non-TNBC Cells.

OBJECTIVE: The progress from Boron Neutron Capture Therapy (BNCT) development urged us to explore new targeted and selective boron carriers. Firstly, we reported the successful synthesis of CCB-2 which exerts a cytotoxic effect against triple negative breast cancer (TNBC) cells. We introduced the new modification of CCB-2 with sugar and alcohol sugars to enhance its solubility in hoping to increase cellular uptake. METHODS: CCB-2 fructose complex (CCB-2-F), CCB-2 sorbitol complex (CCB-2-Sor), and CCB-2 xylitol complex (CCB-2-Xy) were obtained with small size within nano-specific particle. All the compounds were then determined for their cytotoxic activities through MTT assay. RESULTS: All compounds were performed cytotoxic activities against TNBC 4T1 and HER-2 positive MCF-7/HER2 cells with good selectivity when tested in immortalized fibroblast cells. CONCLUSION: Overall, we provided a new modification of CCB-2 through complexation with sugars. Still, further evaluations are needed to develop more efficient CCB-2 as the new candidate of anticancer agent, notably in breast cancer.

Antibody-Based Receptor Targeting Using an Fc-Binding Peptide-Dodecaborate Conjugate and Macropinocytosis Induction for Boron Neutron Capture Therapy.

Boron neutron capture therapy (BNCT) is a radiation method used for cancer therapy. Cellular uptake of boron-10 (10B) atoms induces cancer cell death by the generation of alpha particles and recoiling lithium-7 (7Li) nuclei when the cells are irradiated with low-energy thermal neutrons. Current BNCT technology shows effective therapeutic benefits in refractory cancers such as brain tumors and head and neck cancers. However, improvements to cancer targeting and the cellular uptake efficacy of the boron compounds and the expansion of the diseases treatable by BNCT are highly desirable. In this research, we aimed to develop an antibody-based drug delivery method for BNCT through the use of the Z33 peptide, which shows specific recognition of and interaction with the Fc domain of human IgG, for on-demand receptor targeting. In addition, we determined with an in vitro assay that macropinocytosis induction during antibody-based drug delivery is crucial for the biological activity of BNCT.

The Therapeutic Effects of Dodecaborate Containing Boronophenylalanine for Boron Neutron Capture Therapy in a Rat Brain Tumor Model.

BACKGROUND: The development of effective boron compounds is a major area of research in the study of boron neutron capture therapy (BNCT). We created a novel boron compound, boronophenylalanine-amide alkyl dodecaborate (BADB), for application in BNCT and focused on elucidating how it affected a rat brain tumor model. METHODS: The boron concentration of F98 rat glioma cells following exposure to boronophenylalanine (BPA) (which is currently being utilized clinically) and BADB was evaluated, and the biodistributions in F98 glioma-bearing rats were assessed. In neutron irradiation studies, the in vitro cytotoxicity of each boron compound and the in vivo corresponding therapeutic effect were evaluated in terms of survival time. RESULTS: The survival fractions of the groups irradiated with BPA and BADB were not significantly different. BADB administered for 6 h after the termination of convection-enhanced delivery ensured the highest boron concentration in the tumor (45.8 µg B/g). The median survival time in the BADB in combination with BPA group showed a more significant prolongation of survival than that of the BPA group. CONCLUSION: BADB is a novel boron compound for BNCT that triggers a prolonged survival effect in patients receiving BNCT.