Small-molecule activation of procaspase-3 to caspase-3 as a personalized anticancer strategy

In silico analysis of the interaction of de novo peptides derived from Salvia hispanica with anticancer targetsEvaluation of the anticancer potential of de novo peptides derived from Salvia hispanica through molecular docking

Cancer is one of the leading causes of death worldwide. Conventional cancer therapies are not selective to cancer cells resulting in serious side effects on patients. Thus, the need for complementary treatments that improve the patient's response to cancer therapy is highly important. To predict and evaluate the physicochemical characteristics and potential anticancer activity of the peptides identified from S. hispanica protein fraction <1 kDa through the use of in silico tools. Peptides derived from Salvia hispanica's protein fraction <1 kDa were identified and analyzed for the prediction of their physicochemical properties. The characterized peptide sequences were then submitted to a multi-criteria decision analysis to identify the peptides that possess the characteristics to potentially exert anticancer activity. Through molecular docking analysis, the potential anticancer activity of the Potentially Anticancer Peptide (PAP)-1, PAP-2, PAP-3, PAP-4, and PAP-5 was estimated by their binding interactions with cancer and apoptosis-related molecules. All five evaluated PAPs exhibited strong binding interactions (< -100 kcal/mol). However, PAP-3 showed the lowest binding free energies with several of the targets. Thus, PAP-3 shows potential to be used as a nutraceutical or ingredient for functional foods that adjuvate in cancer treatment. Conclusions: Through the molecular docking studies, the binding of the PAPs to target molecules of interest for cancer treatment was successfully simulated, from which PAP-3 exhibited the lowest binding free energies. Further in vitro and in vivo studies are required to validate the predictions obtained by the in silico analysis.Communicated by Ramaswamy H. Sarma.

Caffeic acid derivative WSY6 protects melanocytes from oxidative stress by reducing ROS production and MAPK activation

Purpose

Vitiligo is a chronic depigmentation disease caused by a loss of functioning melanocytes and melanin from the epidermis. Oxidative stress-induced damage to melanocytes is key in the pathogenesis of vitiligo. WSY6 is a caffeic acid derivative synthesized from epigallocatechin-3-gallate (EGCG). This study is to investigate whether the new chemical WSY6 protected melanocytes from H2O2-induced cell damage and to elucidate the underlying molecular mechanism.

Patients and methods

The present study compared the antioxidative potential of WSY6 with EGCG in hydrogen peroxide (H2O2)-treated PIG1 cells. Western blotting was used to study the protein expression of cyto-c, cleaved-caspase3, cleaved-caspase9, and the activation of MAPK family members, including p38, ERK1/2, JNK and their phosphorylation in melanocytes. ROS assay kit to detect intracellular reactive oxygen species production; CCK8 and lactate dehydrogenase leak assay to detect cytotoxicity.

Results

EGCG and WSY6 ameliorated H2O2-induced oxidative stress damage in PIG1 cells in a does-dependent manner, while WSY6 was much more effective. WSY6 reduced cellular ROS production, cytochrome c release, downregulated caspase-3 and caspase-9 activation. MAPK pathway signaling including phosphorylated p38, ERK and JNK were observed under oxidative stress and can be much protected by pre-treatment of WSY6.

Conclusion

These results indicated that WSY6 could be a more powerful antioxidant than EGCG and protect melanocytes against oxidative cytotoxicity.

Regulation of Peptidase Activity beyond the Active Site in Human Health and Disease

This comprehensive review addresses the intricate and multifaceted regulation of peptidase activity in human health and disease, providing a comprehensive investigation that extends well beyond the boundaries of the active site. Our review focuses on multiple mechanisms and highlights the important role of exosites, allosteric sites, and processes involved in zymogen activation. These mechanisms play a central role in shaping the complex world of peptidase function and are promising potential targets for the development of innovative drugs and therapeutic interventions. The review also briefly discusses the influence of glycosaminoglycans and non-inhibitory binding proteins on enzyme activities. Understanding their role may be a crucial factor in the development of therapeutic strategies. By elucidating the intricate web of regulatory mechanisms that control peptidase activity, this review deepens our understanding in this field and provides a roadmap for various strategies to influence and modulate peptidase activity.

The combination of PAC-1 and entrectinib for the treatment of metastatic uveal melanoma

The treatment of metastatic uveal melanoma remains a major clinical challenge. Procaspase-3, a proapoptotic protein and precursor to the key apoptotic executioner caspase-3, is overexpressed in a wide range of malignancies, and the drug PAC-1 leverages this overexpression to selectively kill cancer cells. Herein, we investigate the efficacy of PAC-1 against uveal melanoma cell lines and report the synergistic combination of PAC-1 and entrectinib. This preclinical activity, tolerability data in mice, and the known clinical effectiveness of these drugs in human cancer patients led to a small Phase 1b study in patients with metastatic uveal melanoma. The combination of PAC-1 and entrectinib was tolerated with no treatment-related grade ≥3 toxicities in these patients. The pharmacokinetics of entrectinib were not affected by PAC-1 treatment. In this small and heavily pretreated initial cohort, stable disease was observed in four out of six patients, with a median progression-free survival of 3.38 months (95% CI 1.6-6.5 months). This study is an initial demonstration that the combination of PAC-1 and entrectinib may warrant further clinical investigation. Clinical trial registration: Clinical Trials.gov: NCT04589832.

The evolution of small molecule enzyme activators

There is a myriad of enzymes within the body responsible for maintaining homeostasis by providing the means to convert substrates to products as and when required. Physiological enzymes are tightly controlled by many signaling pathways and their products subsequently control other pathways. Traditionally, most drug discovery efforts focus on identifying enzyme inhibitors, due to upregulation being prevalent in many diseases and the existence of endogenous substrates that can be modified to afford inhibitor compounds. As enzyme downregulation and reduction of endogenous activators are observed in multiple diseases, the identification of small molecules with the ability to activate enzymes has recently entered the medicinal chemistry toolbox to afford chemical probes and potential therapeutics as an alternative means to intervene in diseases. In this review we highlight the progress made in the identification and advancement of non-kinase enzyme activators and their potential in treating various disease states.

Novel hydrazone-isatin derivatives as potential EGFR inhibitors: Synthesis and in vitro pharmacological profiling

Merging isatin and arylhydrazone moieties constitutes an efficient strategy to access new potential anticancer derivatives. Consequently, 14 hydrazone-isatin derivatives were synthesized and evaluated for their antiproliferative activity against the NCI-60 cancer cell line panel. A kinase assay demonstrated that compound VIIIb inhibited the epidermal growth factor receptor (EGFR), which was confirmed by docking studies, molecular dynamics, and binding free energy calculations. Further characterizations showed that this compound possesses drug-likeness properties, showed a significant decrease of the cell population in the G2/M phase and led to a significant increase in early and late apoptosis, comparable to erlotinib. Also, VIIIb increased the expression of caspase-3 and Bax and decreased the expression of Bcl-2, confirming its potential as a new proapoptotic compound.

Caspase 3 exhibits a yeast metacaspase proteostasis function that protects mitochondria from toxic TDP43 aggregates

Caspase 3 activation is a hallmark of cell death and there is a strong correlation between elevated protease activity and evolving pathology in neurodegenerative disease, such as amyotrophic lateral sclerosis (ALS). At the cellular level, ALS is characterized by protein aggregates and inclusions, comprising the RNA binding protein TDP-43, which are hypothesized to trigger pathogenic activation of caspase 3. However, a growing body of evidence indicates this protease is essential for ensuring cell viability during growth, differentiation and adaptation to stress. Here, we explored whether caspase 3 acts to disperse toxic protein aggregates, a proteostasis activity first ascribed to the distantly related yeast metacaspase ScMCA1. We demonstrate that human caspase 3 can functionally substitute for the ScMCA1 and limit protein aggregation in yeast, including TDP-43 inclusions. Proteomic analysis revealed that disrupting caspase 3 in the same yeast substitution model resulted in detrimental TDP-43/mitochondrial protein associations. Similarly, suppression of caspase 3, in either murine or human skeletal muscle cells, led to accumulation of TDP-43 aggregates and impaired mitochondrial function. These results suggest that caspase 3 is not inherently pathogenic, but may act as a compensatory proteostasis factor, to limit TDP-43 protein inclusions and protect organelle function in aggregation related degenerative disease.

Design and synthesis of novel hexahydrobenzo[4,5]thieno[2,3-d]pyrimidine derivatives as potential anticancer agents with antiangiogenic activity via VEGFR-2 inhibition, and down-regulation of PI3K/AKT/mTOR signaling pathway

New thieno[2,3-d]pyrimidine derivatives were designed and synthesized. The National Cancer Institute (NCI) evaluated the synthesized novel compounds against a panel of 60 tumor cell lines for their antiproliferative activity. Compounds 6b, 6f, and 6g showed potent anticancer activity at 10 µM dose, with mean GI of 20.86%, 76.41%, and 31.49%, respectively. Compound 6f was selected for five-dose concentrations evaluation. Compound 6f scored a submicromolar range of GI50 values against 10 cancer cell lines, indicating broad-spectrum and potent antiproliferative activity. Compound 6f TGI values were recorded in the cytostatic range of 4.02-95.1 µM. In comparison to sorafenib, the tested compounds 6b, 6f, and 6g inhibited VEGFR-2 with IC50 values of 0.290 ± 0.032, 0.066 ± 0.004, and 0.16 ± 0.006 µM, correspondingly. Compound 6f significantly reduced the total VEGFR-2 expression and its phosphorylation. Additionally, 6f reduced the phosphorylation of PI3K, Akt, and mTOR pathway proteins. Moreover, the migratory potential of HUVECs was significantly reduced, after 72 h of treatment with compound 6f, resulting in disrupted wound healing patterns which verified the angiogenesis suppression properties of compound 6f. Compound 6f increased the total apoptosis percentage by 21.27-fold compared to sorafenib, which caused a 24.11-fold increase in the total apoptosis percentage. This apoptotic activity was accompanied by a 7.81-fold increase in the level of apoptotic caspase-3. Furthermore, the cell cycle analysis revealed that the target derivative 6f reduced cellular proliferation and induced an arrest in HCT-15 colon cancer cell cycle at the S phase. Molecular modeling was used to determine the binding profile and affinity of derivative 6f toward the VEGFR-2 active site.

From Natural Sources to Synthetic Derivatives: The Allyl Motif as a Powerful Tool for Fragment-Based Design in Cancer Treatment

Since the beginning of history, natural products have been an abundant source of bioactive molecules for the treatment of different diseases, including cancer. Many allyl derivatives, which have shown anticancer activity both in vitro and in vivo in a large number of cancers, are bioactive molecules found in garlic, cinnamon, nutmeg, or mustard. In addition, synthetic products containing allyl fragments have been developed showing potent anticancer properties. Of particular note is the allyl derivative 17-AAG, which has been evaluated in Phase I and Phase II/III clinical trials for the treatment of multiple myeloma, metastatic melanoma, renal cancer, and breast cancer. In this Perspective, we compile extensive literature evidence with descriptions and discussions of the most recent advances in different natural and synthetic allyl derivatives that could generate cancer drug candidates in the near future.

A novel fluorogenic reporter substrate for 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase gamma-2 (PLCγ2): Application to high-throughput screening for activators to treat Alzheimer's disease

A rare coding variant in PLCγ2 (P522R) expressed in microglia induces a mild activation of enzymatic activity when compared to wild-type. This mutation is reported to be protective against the cognitive decline associated with late-onset Alzheimer's disease (LOAD) and therefore, activation of wild-type PLCγ2 has been suggested as a potential therapeutic target for the prevention and treatment of LOAD. Additionally, PLCγ2 has been associated with other diseases such as cancer and some autoimmune disorders where mutations with much greater increases in PLCγ2 activity have been identified. Here, pharmacological inhibition may provide a therapeutic effect. In order to facilitate our investigation of the activity of PLCγ2, we developed an optimized fluorogenic substrate to monitor enzymatic activity in aqueous solution. This was accomplished by first exploring the spectral properties of various "turn-on" fluorophores. The most promising turn-on fluorophore was incorporated into a water-soluble PLCγ2 reporter substrate, which we named C8CF3-coumarin. The ability of PLCγ2 to enzymatically process C8CF3-coumarin was confirmed, and the kinetics of the reaction were determined. Reaction conditions were optimized to identify small molecule activators, and a pilot screen of the Library of Pharmacologically Active Compounds 1280 (LOPAC₁₂₈₀) was performed with the goal of identifying small molecule activators of PLCγ2. The optimized screening conditions allowed identification of potential PLCγ2 activators and inhibitors, thus demonstrating the feasibility of this approach for high-throughput screening.

Pan-Cancer analysis and experimental validation identify the oncogenic nature of ESPL1: Potential therapeutic target in colorectal cancer

Introduction

Extra spindle pole bodies like 1 (ESPL1) are required to continue the cell cycle, and its primary role is to initiate the final segregation of sister chromatids. Although prior research has revealed a link between ESPL1 and the development of cancer, no systematic pan-cancer analysis has been conducted. Combining multi-omics data with bioinformatics, we have thoroughly described the function of ESPL1 in cancer. In addition, we examined the impact of ESPL1 on the proliferation of numerous cancer cell lines. In addition, the connection between ESPL1 and medication sensitivity was verified using organoids obtained from colorectal cancer patients. All these results confirm the oncogene nature of ESPL1.

Methods

Herein, we downloaded raw data from numerous publicly available databases and then applied R software and online tools to explore the association of ESPL1 expression with prognosis, survival, tumor microenvironment, tumor heterogeneity, and mutational profiles. To validate the oncogene nature of ESPL1, we have performed a knockdown of the target gene in various cancer cell lines to verify the effect of ESPL1 on proliferation and migration. In addition, patients’ derived organoids were used to verify drug sensitivity.

Results

The study found that ESPL1 expression was markedly upregulated in tumorous tissues compared to normal tissues, and high expression of ESPL1 was significantly associated with poor prognosis in a range of cancers. Furthermore, the study revealed that tumors with high ESPL1 expression tended to be more heterogeneous based on various tumor heterogeneity indicators. Enrichment analysis showed that ESPL1 is involved in mediating multiple cancer-related pathways. Notably, the study found that interference with ESPL1 expression significantly inhibited the proliferation of tumor cells. Additionally, the higher the expression of ESPL1 in organoids, the greater the sensitivity to PHA-793887, PAC-1, and AZD7762.

Discussion

Taken together, our study provides evidence that ESPL1 may implicate tumorigenesis and disease progression across multiple cancer types, highlighting its potential utility as both a prognostic indicator and therapeutic target.

Phase I study of procaspase-activating compound-1 (PAC-1) in the treatment of advanced malignancies

BACKGROUND

Procaspase-3 (PC-3) is overexpressed in multiple tumour types and procaspase-activating compound 1 (PAC-1) directly activates PC-3 and induces apoptosis in cancer cells. This report describes the first-in-human, phase I study of PAC-1 assessing maximum tolerated dose, safety, and pharmacokinetics.

METHODS

Modified-Fibonacci dose-escalation 3 + 3 design was used. PAC-1 was administered orally at 7 dose levels (DL) on days 1-21 of a 28-day cycle. Dose-limiting toxicity (DLT) was assessed during the first two cycles of therapy, and pharmacokinetics analysis was conducted on days 1 and 21 of the first cycle. Neurologic and neurocognitive function (NNCF) tests were performed throughout the study.

RESULTS

Forty-eight patients were enrolled with 33 completing ≥2 cycles of therapy and evaluable for DLT. DL 7 (750 mg/day) was established as the recommended phase 2 dose, with grade 1 and 2 neurological adverse events noted, while NNCF testing showed stable neurologic and cognitive evaluations. PAC-1's t1/2 was 28.5 h after multi-dosing, and systemic drug exposures achieved predicted therapeutic concentrations. PAC-1 clinical activity was observed in patients with neuroendocrine tumour (NET) with 2/5 patients achieving durable partial response.

CONCLUSIONS

PAC-1 dose at 750 mg/day was recommended for phase 2 studies. Activity of PAC-1 in treatment-refractory NET warrants further investigation.

CLINICAL TRIAL REGISTRATION

Clinical Trials.gov: NCT02355535.

Beneficial Proapoptotic Effect of Heterobasidion Annosum Extract in Colorectal Cancer Xenograft Mouse Model

Fungal extracts possess potential anticancer activity against many malignant neoplastic diseases. In this research, we focused on the evaluation of Heterobasidion annosum (HA) extract in colorectal cancer in an in vivo model. The mice with implanted DLD-1 human cancer cells were given HA extract, the referential drug-5-fluorouracil (5FU), or were treated with its combination. Thereafter, tumor volume was measured and apoptotic proteins such as caspase-8, caspase-3, p53, Bcl-2, and survivin were analyzed in mice serum with an ELISA assay. The Ki-67 protein was assessed in tumor cells by immunohistochemical examination. The biggest volumes of tumors were confirmed in the DLD-1 group, while the lowest were observed in the population treated with 5FU and/or HA extract. The assessment of apoptosis showed increased concentrations of caspase 8 and p53 protein after the combined administration of 5FU and HA extract. The levels of survivin and Bcl-2 were decreased in all tested groups compared to the DLD-1 group. Moreover, we observed a positive reaction for Ki-67 protein in all tested groups. Our findings confirm the apoptotic effect of extract given alone or with 5FU. The obtained results are innovative and provide a basis for further research concerning the antitumor activity of the HA extract, especially in the range of its interaction with an anticancer chemotherapeutic agent.

Bioinformatics Identification of Therapeutic Gene Targets for Gastric Cancer

INTRODUCTION

The global prevalence of gastric cancer (GC) is increasing, and novel chemotherapeutic targets are needed.

METHODS

We searched for potential biomarkers for GC in three microarray data sets within the Gene Expression Omnibus (GEO) database. FunRich (v3.1.3) was used to perform Gene Ontology (GO) analyses and STRUN and Cytoscape (v3.6.0) were employed to construct a protein-protein interaction (PPI) network. To explore hub gene expression and survival, we used Gene Expression Profiling Interactive Analysis (GEPIA) and Kaplan-Meier (KM) plotter. Drugs that were closely related to key genes were screened by the Gene Set Cancer Analysis (GSCA), and relevant correlations were verified experimentally. We validated that the sensitivity of a GC cell line to these drugs was correlated with fibrillin 1 (FBN1) mRNA expression levels.

RESULTS

We identified 83 upregulated and 133 downregulated differentially expressed genes (DEGs) and these were enriched with regards to their cellular component (extracellular and exosomes), molecular function (extracellular matrix structural constituent and catalytic activity), and biological process (cell growth and/or maintenance and metabolism). The biological pathways most prominently involved were epithelial-to-mesenchymal transition (EMT) and β3 integrin cell surface interactions. For the PPI network, we selected 10 hub genes, and 70% of these were significantly connected to poor overall survival (OS) in patients with GC. We found a significant link between the expression of FBN1 and two small molecule drugs (PAC-1 and PHA-793887).

CONCLUSIONS

Overall, we suggest that these hub genes can be used as biomarkers and novel targets for GC. FBN1 may be associated with drug resistance in gastric cancer.

Anticancer agents incorporating the N-acylhydrazone scaffold: Progress from 2017 to present

The N-acylhydrazone motif has been shown to be particularly adaptable and promising in the area of medicinal chemistry and drug development, due to its significant biological and pharmacological characteristics. Moreover, N-acylhydrazones are appealing synthetic and biological tools because of their simple and straightforward synthesis. This scaffold has emerged as a fundamental building block for the synthesis of bioactive compounds. Particularly, the N-acylhydrazone scaffold served as a base for the synthesis of a number of potent anticancer agents acting via different mechanisms. An updated summary of the anticancer activity of N-acylhydrazone derivatives described in the literature (from 2017 to 2022) is provided in the current review. It discusses the structure-activity relationship (SAR) of N-acylhydrazone derivatives exhibiting anticancer potential, which could be helpful in designing and developing new derivatives as effective antiproliferative candidates in the future.

Phase I dose-escalation study of procaspase-activating compound-1 in combination with temozolomide in patients with recurrent high-grade astrocytomas

BACKGROUND

Procaspase-3 (PC-3) is overexpressed in various tumor types, including gliomas. Targeted PC-3 activation combined with chemotherapy is a novel strategy for treating patients with high-grade gliomas, with promising preclinical activity. This study aimed to define safety and tolerability of procaspase-activating compound-1 (PAC-1) in combination with temozolomide (TMZ) for patients with recurrent high-grade astrocytomas.

METHODS

A modified-Fibonacci dose-escalation 3 + 3 design was used. PAC-1 was administered at increasing dose levels (DL; DL1 = 375 mg) on days 1-21, in combination with TMZ 150 mg/m2/5 days, per 28-day cycle. Dose-limiting toxicity was assessed during the first 2 cycles. Neurocognitive function (NCF) testing was conducted throughout the study.

RESULTS

Eighteen patients were enrolled (13 GBM, IDH-wild type; 2 astrocytoma, IDH-mutant, grade 3; 3 astrocytoma, IDH-mutant, grade 4). Dose escalation was discontinued after DL3 (ie, PAC-1, 625 mg) due to lack of additional funding. Grade 3 toxicity was observed in 1 patient at DL1 (elevated liver transaminases) and 1 at DL 2 (headache). Two partial responses were observed at DL1 in patients with GBM, O6-methylguanine-DNA methyltransferase (MGMT) promoter methylated. Two patients had stable disease, and 11 experienced progression. NCF testing did not show a clear relationship between PAC-1 dose, treatment duration, and declines in NCF.

CONCLUSIONS

Combination of PAC-1 and TMZ was well tolerated up to 625 mg orally daily and TMZ orally 150 mg/m2/5 days per 28-day cycle. The maximum tolerated dose was not reached. Further dose escalation of PAC-1 in combination with TMZ is advised before conducting a formal prospective efficacy study in this patient population.

Differential Inhibite Effect of Xanthohumol on HepG2 Cells and Primary Hepatocytes

Xanthohumol (XN) is the major prenylated chalcone of the female inflorescences (cone) of the hop plant ( Humulus lupulus). It is also a constituent of beer, the major dietary source of prenylated flavonoids. It has shown strong antitumorigenic activity towards various types of cancer cells. In the present study, we show the impact on human hepatocarcinoma cell line HepG2 cell and potential adverse effects on rat primary hepatocytes. Cell growth/viability assay (MTT) demonstrated that HepG2 cells are highly sensitive to XN at a concentration range of 25-100 μM. The primary mode of tumor cell destruction was apoptosis as demonstrated by the binding of Annexin Ⅴ-FITC, we show that XN at a concentration of 25 μM induced apoptosis in HepG2. Further evidence that XN kills HepG2 by inducing apoptosis was provided by the impact of XN on the cleavage of PARP-1 and caspases-3. In contrast, XN concentrations up to 100 μM did not affect viability of primary rat hepatocytes in vitro, meanwhile, XN did not induce the apoptosis of primary rat hepatocytes in vitro . In summary, our data provide a rationale for clinical evaluation of XN for the treatment of liver cancer.

Immune depletion of the methylated phenotype of colon cancer is closely related to resistance to immune checkpoint inhibitors

Background

Molecular typing based on single omics data has its limitations and requires effective integration of multiple omics data for tumor typing of colorectal cancer (CRC).

Methods

Transcriptome expression, DNA methylation, somatic mutation, clinicopathological information, and copy number variation were retrieved from TCGA, UCSC Xena, cBioPortal, FireBrowse, or GEO. After pre-processing and calculating the clustering prediction index (CPI) with gap statistics, integrative clustering analysis was conducted via MOVICS. The tumor microenvironment (TME) was deconvolved using several algorithms such as GSVA, MCPcounter, ESTIMATE, and PCA. The metabolism-relevant pathways were extracted through ssGSEA. Differential analysis was based on limma and enrichment analysis was carried out by Enrichr. DNA methylation and transcriptome expression were integrated via ELMER. Finally, nearest template or hemotherapeutic sensitivity prediction was conducted using NTP or pRRophetic.

Results

Three molecular subtypes (CS1, CS2, and CS3) were recognized by integrating transcriptome, DNA methylation, and driver mutations. CRC patients in CS3 had the most favorable prognosis. A total of 90 differentially mutated genes among the three CSs were obtained, and CS3 displayed the highest tumor mutation burden (TMB), while significant instability across the entire chromosome was observed in the CS2 group. A total of 30 upregulated mRNAs served as classifiers were identified and the similar diversity in clinical outcomes of CS3 was validated in four external datasets. The heterogeneity in the TME and metabolism-related pathways were also observed in the three CSs. Furthermore, we found CS2 tended to loss methylations while CS3 tended to gain methylations. Univariate and multivariate Cox regression revealed that the subtypes were independent prognostic factors. For the drug sensitivity analysis, we found patients in CS2 were more sensitive to ABT.263, NSC.87877, BIRB.0796, and PAC.1. By Integrating with the DNA mutation and RNA expression in CS3, we identified that SOX9, a specific marker of CS3, was higher in the tumor than tumor adjacent by IHC in the in-house cohort and public cohort.

Conclusion

The molecular subtypes based on integrated multi-omics uncovered new insights into the prognosis, mechanisms, and clinical therapeutic targets for CRC.

Kaempferol attenuates viability of ex-vivo cultured post-NACT breast tumor explants through downregulation of p53 induced stemness, inflammation and apoptosis evasion pathways

Early onset of chemotherapy evasion is a therapeutic challenge. Chemotherapy-induced upregulation of stem cell markers imparts invasiveness and metastatic property to the resident tumor. The efficacy of Kaempferol in attenuating epithelial to mesenchymal transition has earlier been established in the breast cancer cell. In our study population, progression-free survival was observed to be statistically more significant in post-NACT low-grade tumors than the high-grade tumors. Further, in post-NACT TNBCs, high-grade tumors showed a preponderance of strong nuclear p53 expression and very low expression of Caspase 3, indicating that, altered p53 expression predisposes these tumors to apoptosis escape and up-regulation of stemness markers. Herein, we report the robust efficacy of Kaempferol on ex-vivo grown breast tumors, derived from post-NACT TNBC patients, through downregulation of nuclear p53, CD44, ALDH1, NANOG, MDR1, Ki67, BCL2 and upregulation of Caspase 3. Such tumors also showed concurrent deregulated RNA and protein expression of CD44, NANOG, ALDH1 and MDR1 with upregulation of Caspase 3 and cleaved Caspase 3, upon Kaempferol treatment. Validation of efficacy of the treatment dosage of Kaempferol through immunophenotyping on MDA-MB-231, suggested that Kaempferol at its IC-50 dosage was effective against CD44 and CD326 positive breast cancer through deregulating their expression. Protein-protein interaction network through STRING pathway analysis and co-expression study of candidate proteins showed the highest degree of co-expression of p53 and KI-67, CD44, NF- kappaB, ALDH1, NANOG, MDR1, and BCL2. Thus, potentially targetable oncogenic protein markers, that are susceptible to downregulation by Kaempferol, provides insight into biomarker-driven therapeutic approaches with it.

Systematic and mechanistic analysis of AuNP-induced nanotoxicity for risk assessment of nanomedicine

For decades, nanoparticles (NPs) have been widely implemented in various biomedical fields due to their unique optical, thermal, and tunable properties. Particularly, gold nanoparticles (AuNPs) have opened new frontiers in sensing, targeted drug delivery, imaging, and photodynamic therapy, showing promising results for the treatment of various intractable diseases that affect quality of life and longevity. Despite the tremendous achievements of AuNPs-based approaches in biomedical applications, few AuNP-based nanomedicines have been evaluated in clinical trials, which is likely due to a shortage of understanding of the biological and pathological effects of AuNPs. The biological fate of AuNPs is tightly related to a variety of physicochemical parameters including size, shape, chemical structure of ligands, charge, and protein corona, and therefore evaluating the effects of these parameters on specific biological interactions is a major ongoing challenge. Therefore, this review focuses on ongoing nanotoxicology studies that aim to characterize the effect of various AuNP characteristics on AuNP-induced toxicity. Specifically, we focus on understanding how each parameter alters the specific biological interactions of AuNPs via mechanistic analysis of nano-bio interactions. We also discuss different cellular functions affected by AuNP treatment (e.g., cell motility, ROS generation, interaction with DNA, and immune response) to understand their potential human health risks. The information discussed herein could contribute to the safe usage of nanomedicine by providing a basis for appropriate risk assessment and for the development of nano-QSAR models.

PDGF-BB-derived supramolecular hydrogel for promoting skin wound healing

Chronic wounds represent a major challenge to the present healthcare system. In recent decades, many topical therapies have been investigated for the treatment of chronic wounds, including different types of wound dressings, antimicrobial agents, and cell therapy. Platelet-derived growth factor (PDGF) plays an important role in wound healing and has been approved for treatment of wounds related to diabetes mellitus. However, the high cost and short retention time of PDGF protein have limited its wide application. To overcome this challenge, we designed a PDGF-mimicking peptide by connecting PDGF epitope VRKIEIVRKK and self-assembling motif derived from β-amyloid peptide. The resultant peptide can self-assemble into a fibril-rich network and leads to supramolecular hydrogelation with good stability. The hydrophilic epitope can be exposed on the surface of nanofibrils, which might contribute to the binding and activation of PDGF receptors. The forming hydrogel is able to induce the growth and migration of vascular endothelial cells and promote the formation of vascular branches. In the full-thickness skin wounds of healthy mice, after the application of the hydrogel, the density of neovascularization marked by CD31 was greater than that in the control group on Day 3. Larger collagen deposition and a thicker epidermis were observed on Day 12. These results demonstrate that the hydrogel can stimulate collagen deposition and angiogenesis, enhance skin regeneration, and show an excellent therapeutic effect. Taken together, this work not only provides new insight into the design of bioactive peptides but also offers a promising biomaterial for wound healing.

Design, synthesis and evaluation of novel 2-oxoindoline-based acetohydrazides as antitumor agents

In our search for novel small molecules activating procaspase-3, we have designed and synthesized two series of novel (E)-N'-arylidene-2-(2-oxoindolin-1-yl)acetohydrazides (4) and (Z)-2-(5-substituted-2-oxoindolin-1-yl)-N'-(2-oxoindolin-3-ylidene)acetohydrazides (5). Cytotoxic evaluation revealed that the compounds showed notable cytotoxicity toward three human cancer cell lines: colon cancer SW620, prostate cancer PC-3, and lung cancer NCI-H23. Especially, six compounds, including 4f–h and 4n–p, exhibited cytotoxicity equal or superior to positive control PAC-1, the first procaspase-3 activating compound. The most potent compound 4o was three- to five-fold more cytotoxic than PAC-1 in three cancer cell lines tested. Analysis of compounds effects on cell cycle and apoptosis demonstrated that the representative compounds 4f, 4h, 4n, 4o and 4p (especially 4o) accumulated U937 cells in S phase and substantially induced late cellular apoptosis. The results show that compound 4o would serve as a template for further design and development of novel anticancer agents.

Design, Synthesis and Evaluation of Novel (E)-N'-((1-(4-chlorobenzyl)-1H-indol-3-yl)methylene)-2-(4-oxoquinazolin-3(4H)-yl)acetohydrazides as Antitumor Agents

BACKGROUND

Herein, we have designed and synthesized a series of the novel (E)-N'-((1-(4-chlorobenzyl)-1H-indol-3-yl)methylene)-2-(4-oxoquinazolin-3(4H)-yl)acetohydrazides (5) as potent small molecules activating procaspase-3. The compounds were designed by the amalgamation of structural features of PAC-1 (the first procaspase-3 activator) and oncrasin-1, one potential anticancer agent.

METHODS

The target acetohydrazides (5a-m) were prepared via the Niementowski condensation of anthranilic acid (1a) or 5-substituted-2-aminobenzoic acid (1b-m) and formamide. The compound libraries were evaluated for their cytotoxicity, caspase-3 activation, cell cycle analysis, and apoptosis. In addition, computational chemistry is also performed.

RESULTS

A biological evaluation revealed that all thirteen compounds designed and synthesized showed strong cytotoxicity against three human cancer cell lines (SW620, colon cancer; PC-3, prostate cancer; NCI-H23, lung cancer) with eight compounds (5a, 5c-i, 5k), which were clearly more potent than both PAC-1 and oncrasin-1. In this series, four compounds including 5c, 5e, 5f, and 5h, were the most potent members with approximately 4- to 5-fold stronger than the reference compounds PAC-1 and oncrasin-1 in terms of IC50. In comparison to 5-FU, these compounds were even 18- to 29-fold more potent in terms of cytotoxicity in three human cell lines tested. In the caspase activation assay, the caspase activity was activated to 285% by compound 5e in comparison to PAC-1, the first procaspase activating compound, which was used as a control. Our docking simulation revealed that compound 5e was a potent allosteric inhibitor of procaspase-3 through chelation of inhibitory zinc ion. Physicochemical and ADMET calculations for 5e provided useful information of its suitable absorption profile and some toxicological effects that need further optimization to be developed as a promising anticancer agent.

CONCLUSION

Compound 5e has emerged as a potential hit for further design and development of caspases activators and anticancer agents.

Synthesis, biological evaluation, and in silico studies of potential activators of apoptosis and carbonic anhydrase inhibitors on isatin-5-sulfonamide scaffold

Carbonic anhydrase IX is a promising target for the search for new antitumor compounds with improved properties. Using the molecular hybridization approach, on the basis of structures of a selective carbonic anhydrase IX inhibitor 3 and an activator of apoptosis 2 (1), a series of 1-substituted isatin-5-sulfonamides 5a-5u were designed and synthesized. The study of the inhibitory activity of isatin-5-sulfonamides showed the ability to inhibit I, II, IX, XII isoforms at nano- and micromolar concentrations. Docking of compounds 5e and 5k into the active site of II and IX carbonic anhydrase isoforms showed the coordination of sulfonamidate anions with zinc cations, as well as a number of additional hydrophobic interactions. The trifluoromethylthio derivative 5r suppressed the growth of tumor cells at low micromolar concentrations, maintaining activity on resistant lines and under hypoxic conditions. Immunoblotting of MCF7 cells treated with the 5r revealed its antiestrogenic activity and ability to activate apoptosis in tumor cells.

Enterovirus A71 2B Inhibits Interferon-Activated JAK/STAT Signaling by Inducing Caspase-3-Dependent Karyopherin-α1 Degradation

Enterovirus A71 (EV-A71) is a major pathogen that causes the hand, foot, and mouth disease, which could be fatal with neurological complications in children. The underlying mechanism for the severe pathogenicity remains obscure, but impaired or aberrant innate immunity is considered to play a key role in viral pathogenesis. We reported previously that EV-A71 suppressed type I interferon (IFN) responses by inducing degradation of karyopherin-α1 (KPNA1), a component of the p-STAT1/2 complex. In this report, we showed that 2B, a non-structural protein of EV-A71, was critical to the suppression of the IFN-α-induced type I response in infected cells. Among viral proteins, 2B was the only one that was involved in the degradation of KPNA1, which impeded the formation of the p-STAT1/2/KPNA1 complex and blocked the translocation of p-STAT1/2 into the nucleus upon IFN-α stimulation. Degradation of KPNA1 induced by 2B can be inhibited in the cells pre-treated with Z-DEVD-FMK, a caspase-3 inhibitor, or siRNA targeting caspase-3, indicating that 2B-induced degradation of KPNA1 was caspase-3 dependent. The mechanism by which 2B functioned in the dysregulation of the IFN signaling was analyzed and a putative hydrophilic domain (H1) in the N-terminus of 2B was characterized to be critical for the release of cytochrome c into the cytosol for the activation of pro-caspase-3. We generated an EV-A71 infectious clone (rD1), which was deficient of the H1 domain. In rD1-infected cells, degradation of KPNA1 was relieved and the infected cells were more sensitive to IFN-α, leading to decreased viral replication, in comparison to the cells infected with the virus carrying a full length 2B. Our findings demonstrate that EV-A71 2B protein plays an important role in dysregulating JAK-STAT signaling through its involvement in promoting caspase-3 dependent degradation of KPNA1, which represents a novel strategy employed by EV-A71 to evade host antiviral innate immunity.

Design, synthesis, anticancer evaluation, and molecular modelling studies of novel tolmetin derivatives as potential VEGFR-2 inhibitors and apoptosis inducers

Novel tolmetin derivatives 5a-f to 8a-c were designed, synthesised, and evaluated for antiproliferative activity by NCI (USA) against a panel of 60 tumour cell lines. The cytotoxic activity of the most active tolmetin derivatives 5b and 5c was examined against HL-60, HCT-15, and UO-31 tumour cell lines. Compound 5b was found to be the most potent derivative against HL-60, HCT-15, and UO-31 cell lines with IC50 values of 10.32 ± 0.55, 6.62 ± 0.35, and 7.69 ± 0.41 µM, respectively. Molecular modelling studies of derivative 5b towards the VEGFR-2 active site were performed. Compound 5b displayed high inhibitory activity against VEGFR-2 (IC50 = 0.20 µM). It extremely reduced the HUVECs migration potential exhibiting deeply reduced wound healing patterns after 72 h. It induced apoptosis in HCT-15 cells (52.72-fold). This evidence was supported by an increase in the level of apoptotic caspases-3, -8, and -9 by 7.808-, 1.867-, and 7.622-fold, respectively. Compound 5b arrested the cell cycle in the G0/G1 phase. Furthermore, the ADME studies showed that compound 5b possessed promising pharmacokinetic properties.

Mucin 1 as a Molecular Target of a Novel Diisoquinoline Derivative Combined with Anti-MUC1 Antibody in AGS Gastric Cancer Cells

BACKGROUND

The aim of the study was to examine the molecular mechanism of the anticancer action of a monoclonal antibody against MUC1 and a diisoquinoline derivative (OM-86II) in human gastric cancer cells.

METHODS

The cell viability was measured by the MTT assay. The disruption of mitochondrial membrane potential and activity of caspase-8 and caspase-9 was performed by flow cytometry. Fluorescent microscopy was used to confirm the proapoptotic effect of compounds. LC3A, LC3B and Beclin-1 concentrations were analyzed to check the influence of the compounds on induction of autophagy. ELISA assessments were performed to measure the concentration of mTOR, sICAM1, MMP-2, MMP-9 and pro-apoptotic Bax.

RESULTS

The anti-MUC1 antibody with the diisoquinoline derivative (OM-86II) significantly reduced gastric cancer cells' viability. This was accompanied by an increase in caspase-8 and caspase-9 activity as well as high concentrations of pro-apoptotic Bax. We also proved that the anti-MUC1 antibody with OM-86II decreased the concentrations of MMP-9, sICAM1 and mTOR in gastric cancer cells. After 48 h of incubation with such a combination, we observed higher levels of the crucial component of autophagosomes (LC3) and Beclin-1.

CONCLUSIONS

Our study proved that the anti-MUC1 antibody sensitizes human gastric cancer cells to the novel diisoquinoline derivative (OM-86II) via induction of apoptosis and autophagy, and inhibition of selected proteins such as mTOR, sICAM1 and MMP-9.

Design, synthesis, and evaluation of novel (E)-N'-(3-allyl-2-hydroxy)benzylidene-2-(4-oxoquinazolin-3(4H)-yl)acetohydrazides as antitumor agents

In our continuing search for novel small-molecule anticancer agents, we designed and synthesized a series of novel (E)-N'-(3-allyl-2-hydroxy)benzylidene-2-(4-oxoquinazolin-3(4H)-yl)acetohydrazides (5), focusing on the modification of substitution in the quinazolin-4(3H)-one moiety. The biological evaluation showed that all 13 designed and synthesized compounds displayed significant cytotoxicity against three human cancer cell lines (SW620, colon cancer; PC-3, prostate cancer; NCI-H23, lung cancer). The most potent compound 5l displayed cytotoxicity up to 213-fold more potent than 5-fluorouracil and 87-fold more potent than PAC-1, the first procaspase-activating compound. Structure-activity relationship analysis revealed that substitution of either electron-withdrawing or electron-releasing groups at positions 6 or 7 on the quinazolin-4(3H)-4-one moiety increased the cytotoxicity of the compounds, but substitution at position 6 seemed to be more favorable. In the caspase activation assay, compound 5l was found to activate the caspase activity by 291% in comparison to PAC-1, which was used as a control. Further docking simulation also revealed that this compound may be a potent allosteric inhibitor of procaspase-3 through chelation of the inhibitory zinc ion. Physicochemical and ADMET calculations for 5l provided useful information of its suitable absorption profile and some toxicological effects that need further optimization to be developed as a promising anticancer agent.

Evaluation of a procaspase-3 activator with hydroxyurea or temozolomide against high-grade meningioma in cell culture and canine cancer patients

BACKGROUND

High-grade meningioma is an aggressive type of brain cancer that is often recalcitrant to surgery and radiotherapy, leading to poor overall survival. Currently, there are no FDA-approved drugs for meningioma, highlighting the need for new therapeutic options, but development is challenging due to the lack of predictive preclinical models.

METHODS

To leverage the known overexpression of procaspase-3 in meningioma, PAC-1, a blood-brain barrier penetrant procaspase-3 activator, was evaluated for its ability to induce apoptosis in meningioma cells. To enhance the effects of PAC-1, combinations with either hydroxyurea or temozolomide were explored in cell culture. Both combinations were further investigated in small groups of canine meningioma patients and assessed by MRI, and the novel apoptosis tracer, [18F]C-SNAT4, was evaluated in patients treated with PAC-1 + HU.

RESULTS

In meningioma cell lines in culture, PAC-1 + HU are synergistic while PAC-1 + TMZ show additive-to-synergistic effects. In canine meningioma patients, PAC-1 + HU led to stabilization of disease and no change in apoptosis within the tumor, whereas PAC-1 + TMZ reduced tumor burden in all three canine patients treated.

CONCLUSIONS

Our results suggest PAC-1 + TMZ as a potentially efficacious combination for the treatment of human meningioma, and also demonstrate the utility of including pet dogs with meningioma as a means to assess anticancer strategies for this common brain tumor.

The Theoretical Model, Method, and Applications of Scattering Photon Burst Counting Based on an Objective Scanning Technique

Scattering photon burst counting (SPBC) is a single-particle detection method, which is based on measuring scattering photon bursting of single nanoparticles through a detection volume of <1 fL. Although SPBC has been used for bioassays and analysis of nanoparticles, it is necessary to establish its theoretical model and develop a new detection mode in order to further enhance its sensitivity and enlarge its application fields. In this paper, we proposed a theoretical model for the confocal SPBC method and developed a novel SPBC detection mode using the fast objective scanning technique. The computer simulations and experiments documented that this model well describes the relation between photon counts and experimental parameters (such as nanoparticle concentration and diameter, temperature, and viscosity). Based on this model, we developed a novel SPBC detection mode by using the fast objective scanning technique. Compared to the current confocal SPBC method, the sensitivity of this new method was significantly increased due to the significantly increased photon counts per sampling time, the linear detection range is from 0.9 to 90 pM, and the limit of detection is reduced to 40 fM for 30 nm gold nanoparticles. Furthermore, this new method was successfully applied to determine the enzyme activity of caspase-3 and evaluate the inhibition effectiveness of some inhibitors.

Angiotensin-converting enzyme 2 alleviates pulmonary artery hypertension through inhibition of focal adhesion kinase expression

Focal adhesion kinase (FAK) is an important therapeutic target in pulmonary artery hypertension (PAH); however, the mechanism of its activation remains unknown. The present study aimed to investigate whether angiotensin-converting enzyme 2 (ACE2) could regulate FAK and alleviate PAH in a rat model of PAH established with a single administration of monocrotaline followed by continuous hypoxia treatment. In the current study, right ventricular pressure, body weight and the right ventricular hypertrophy index were measured, and hematoxylin-eosin staining was performed on lung tissues to determine whether the modeling was successful. Changes in the serum levels of FAK were measured using an ELISA kit to evaluate the association between ACE2 and FAK. The mRNA expression levels of ACE2, FAK, caspase-3 and survivin were determined using reverse transcription-quantitative PCR (RT-qPCR). The protein expression levels of ACE2, phosphorylated FAK/FAK, cleaved caspase-3/pro-caspase-3 and survivin were determined via western blotting. Immunohistochemistry was applied to detect the expression of FAK around the pulmonary arterioles. Apoptosis of smooth muscle cells around pulmonary arterioles was observed by TUNEL staining. After treatment with the ACE2 activator DIZE or inhibitor DX-600, the results demonstrated that ACE2 reduced PAH-induced changes in arteriole morphology compared with the control. It also inhibited FAK expression in serum. WB and RT-qPCR results suggested that ACE2 inhibited the expression of FAK and pathway-related proteins, and promoted caspase-3 expression. Additionally, ACE2 reduced FAK expression around the pulmonary arterioles and promoted smooth muscle cell apoptosis. The results indicated that ACE2 activation inhibited FAK expression, leading to alleviation of the symptoms of PAH.

EIF4A3-mediated hsa_circ_0088088 promotes the carcinogenesis of breast cancer by sponging miR-135-5p

Circular RNAs have participated in oncology progress. Nevertheless, the potential mechanisms are not completely understood. We intended to inspect the functions of hsa_circ_0088088 on breast malignancy, together with the possible mechanism(s). hsa_circ_0088088 expression in breast malignancy was studied using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). The overall survival was studied by the Kaplan-Meier curve. The biological functions of hsa_circ_0088088 aberrant expression on cell growth and metastasis were evaluated in MDA-MB-231 cells. Bioinformatics analysis, RNA immunoprecipitation (RIP), and qRT-PCR were accomplished to confirm the possible regulatory effects of eukaryotic initiation factor 4A3 (EIF4A3) on the biogenesis of hsa_circ_0088088. Furthermore, a dual-luciferase reporter assay, qRT-PCR, and RNA pull-down assay were used to confirm the association between the hsa_circ_0088088 and miR-135-5p in MDA-MB-231 cells. hsa_circ_0088088 was upregulated in the tumor tissues and cells, and higher expression presented an unfavorable prognosis. hsa_circ_0088088 overexpression promoted cell growth and metastasis in MDA-MB-231 cells. EIF4A3 was found to positively regulate hsa_circ_0088088. Furthermore, we confirmed that hsa_circ_0088088 sponges miR-135-5p and directly targets miR-135-5p with respect to the cell growth and metastasis in MDA-MB-231 cells. Our data suggest that EIF4A3-induced hsa_circ_0088088 stimulates the carcinogenic effects of breast tumors by sponging miR-135-5p.

SAR131675 Receptor Tyrosine Kinase Inhibitor Induces Apoptosis through Bcl-2/Bax/Cyto c Mitochondrial Pathway in Human Umbilical Vein Endothelial Cells

BACKGROUND

Tyrosine kinase inhibitors (TKIs) can be used to inhibit cancer cell proliferation by targeting the vascular endothelial growth factor receptor (VEGFR) family. SAR131675 is a highly selective receptor tyrosine kinase inhibitor to VEGFR3 that reveals the inhibitory effect on proliferation in human lymphatic endothelial cells. However, the molecular mechanisms underlying this process are generally unclear.

OBJECTIVE

This study was performed to investigate the possible involvement of the Bcl-2/Bax/Cyto c apoptosis pathway in human umbilical vein endothelial cells (HUVECs). In addition, the role of reactive oxygen species (ROS) and mitochondrial membrane potential was evaluated.

METHODS

The effect of SAR131675 on HUVEC cell viability was evaluated by MTT assay. The activity of SAR131675 in inducing apoptosis was carried out through the detection of Annexin V-FITC/PI signal by flow cytometry. To determine the mechanisms underlying SAR131675 induced apoptosis, the mitochondrial membrane potential, ROS generation, the activity of caspase-3, and expression of apoptosis-related proteins such as Bcl-2, Bax, and cytochrome c were evaluated in HUVECs.

RESULTS

SAR131675 significantly inhibited cell viability and induced apoptosis in HUVECs in a dose-dependent manner. Moreover, SAR131675 induced mitochondrial dysfunction, ROS generation, Bcl-2 down-regulation, Bax up-regulation, cytochrome c release, and caspase-3 activation, which displays features of the mitochondria-dependent apoptosis signaling pathway.

CONCLUSION

Our present data demonstrated that SAR131675-induced cytotoxicity in HUVECs is associated with the mitochondria apoptotic pathway. These results suggest that further studies are required to fully elucidate the role of TKIs in these cellular processes.

Synthesis, Antiproliferative activity, and apoptotic profile of New Derivatives from the Meta Stable Benzoxazinone Scaffold

BACKGROUND

Cancer exerts a huge strain on the health system. The emerging resistance to the current chemotherapies demands the continuous development of new anticancer agents with lower cost, higher efficacy, and greater specificity.

OBJECTIVE

Development of selective small molecules targeted anticancer agents.

METHODS

The behavior of benzoxazinone 2 towards nitrogen nucleophiles such as hydrazine hydrate, formamide, ethanolamine, aromatic amines, and thiosemcarbazide was described. The behavior of the amino quinazolinone 3 towards carbon electrophiles and P2S5 was also investigated. The antiproliferative activity of 17 new benzoxazinone derivatives was examined against the growth of three human cancer cell lines; liver HepG2, breast MCF-7, and colon HCT-29, in addition to the normal human fibroblasts WI-38 and the selectivity index was calculated. The possible molecular pathways such as the cell cycle and apoptosis were investigated.

RESULTS

Derivatives 3, 7, 8, 10, 13, and 15 had a significant (less than 10 µM) antiproliferative activity against the three cancer cell lines investigated. Derivative 7 showed the best antiproliferative profile comparable to that of doxorubicin. The selectivity index for all the effective derivatives ranged from ~5-12 folds indicating high selectivity against the cancer cells. Derivative 15 caused ~ 7-fold and 8-fold inductions in the expression of p53 and caspase3, respectively. It also caused a ~ 60% reduction in the expression of both topoisomerase II (topoII) and cyclin-dependent kinase 1 (cdk1). Derivatives 3, 7, and 8 had a similar profile; ~ 6-8-fold increases in the expression of p53 and caspase3 but these compounds were devoid of any significant effect on the expression of topoII and cdk1. Derivatives 10 and 13 were also similar and resulted in a ~6-fold elevation in the expression of caspase3, and more than 60% downregulation in the expression of topoII. The results of the gene expression of topoII and caspase 3 were confirmed by the measurement of the topoII concentration and caspase3 activity in the HepG2 cells.

CONCLUSION

Six derivatives exerted their antiproliferative activity by arresting the cell cycle (decreasing cdk1), preventing the DNA duplication (downregulating topo II), and by inducing apoptosis (inducing p53 and caspase3). One common feature in all the six active derivatives is the presence of free amino group. These compounds have merit for further investigations.

Evaluation of the antitumor activity of a series of the pincer-type metallocomplexes produced from isonicotinohydrazide derivative

In this work we report on the antitumor properties of a series of pincer-type metallocomplexes [Hg₂(HL-keto)Cl₄]_n (1), [Hg(HL-keto)I₂] (2) and [Mn(HL-zwitterion)Cl₂]∙MeOH (3∙MeOH), derived from N'-(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide (HL) and corresponding metal salts. The Hg(II) and Mn(II) salts are chelated by the keto (HL-keto) or zwitterionic (HL-zwitterion) form of HL, respectively. The cytotoxic effects of these compounds have been accessed against lung adenocarcinoma (A549) and hepatocellular carcinoma (HepG2 and Huh7) cell lines. Complexes 1 and 2 were found to be most efficient against the cell line Huh7 with IC₅₀ value of 2.56 and 9.90 μM, respectively, while they exhibit moderate activity towards cell lines A549 and HepG2, as evidenced from IC₅₀ values in the range 27.98-56.99 μM. Complex 3∙MeOH is less efficient towards all the three cell lines with relatively high IC₅₀ values. The mechanisms of the metallocomplexes killing the aforementioned cells were elucidated by flow cytometry, colony formation and polymerase chain reaction (PCR) analysis of apoptosis related expression of the genes. The results of the cytotoxic effects and antitumor activity on different cell lines are affected by the metal nature and the presence of the coordinated halide.

Caspase-3: A primary target for natural and synthetic compounds for cancer therapy

Caspases, a group of protease enzymes (cysteine proteases), exist as inactive zymogens in the cells and execute apoptosis (programmed cell death). Caspase-3, an executioner caspase, plays an imperative role in apoptosis and becomes a primary target for cancer treatment. A number of analogues of quinazoline, quinazolinone, indoloquinazolines, quinone, naphthoquinones, pyrroloiminoquinones, styrylquinolines, tetheredtetrahydroquinoline, fluoroquinolone, thiosemicarbazones, benzotriazole, pyrimidines, chalcone, and carbazoles have been reported till date, representing caspase-3 mediated apoptosis for cancer therapy. Simultaneously, plant isolates, including lysicamine, podophyllotoxin, and majoranolide, have also been claimed for caspase-3-mediated apoptosis-induced cytotoxicity. Procaspase-activating compound-1 (PAC-1) is the first FDA approved orphan drug, and its synthetic derivative WF-208 also showed fascinating caspase-3 mediated anticancer activity. Till date, a large number of compounds have been reported and patented for their caspase-3-mediated cytotoxicity and now scientist is also focusing to introduce new compounds in market to encompass anticancer activity.

Procaspase-Activating Compound-1 Synergizes with TRAIL to Induce Apoptosis in Established Granulosa Cell Tumor Cell Line (KGN) and Explanted Patient Granulosa Cell Tumor Cells In Vitro

Granulosa cell tumors (GCT) constitute only ~5% of ovarian neoplasms yet have significant consequences, as up to 80% of women with recurrent GCT will die of the disease. This study investigated the effectiveness of procaspase-activating compound 1 (PAC-1), an activator of procaspase-3, in treating adult GCT (AGCT) in combination with selected apoptosis-inducing agents. Sensitivity of the AGCT cell line KGN to these drugs, alone or in combination with PAC-1, was tested using a viability assay. Our results show a wide range in cytotoxic activity among the agents tested. Synergy with PAC-1 was most pronounced, both empirically and by mathematical modelling, when combined with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). This combination showed rapid kinetics of apoptosis induction as determined by caspase-3 activity, and strongly synergistic killing of both KGN as well as patient samples of primary and recurrent AGCT. We have demonstrated that the novel combination of two pro-apoptotic agents, TRAIL and PAC-1, significantly amplified the induction of apoptosis in AGCT cells, warranting further investigation of this combination as a potential therapy for AGCT.

Design, Synthesis, Molecular Modeling and Antitumor Evaluation of Novel Indolyl-Pyrimidine Derivatives with EGFR Inhibitory Activity

Scaffolds hybridization is a well-known drug design strategy for antitumor agents. Herein, series of novel indolyl-pyrimidine hybrids were synthesized and evaluated in vitro and in vivo for their antitumor activity. The in vitro antiproliferative activity of all compounds was obtained against MCF-7, HepG2, and HCT-116 cancer cell lines, as well as against WI38 normal cells using the resazurin assay. Compounds 1-4 showed broad spectrum cytotoxic activity against all these cancer cell lines compared to normal cells. Compound 4g showed potent antiproliferative activity against these cell lines (IC₅₀ = 5.1, 5.02, and 6.6 μM, respectively) comparable to the standard treatment (5-FU and erlotinib). In addition, the most promising group of compounds was further evaluated for their in vivo antitumor efficacy against EAC tumor bearing mice. Notably, compound 4g showed the most potent in vivo antitumor activity. The most active compounds were evaluated for their EGFR inhibitory (range 53-79%) activity. Compound 4g was found to be the most active compound against EGFR (IC₅₀ = 0.25 µM) showing equipotency as the reference treatment (erlotinib). Molecular modeling study was performed on compound 4g revealed a proper binding of this compound inside the EGFR active site comparable to erlotinib. The data suggest that compound 4g could be used as a potential anticancer agent.