Bengamide Analogues Show A Potent Antitumor Activity against Colon Cancer Cells: A Preliminary Study

The potential of marine natural Products: Recent Advances in the discovery of Anti-Tuberculosis agents

Tuberculosis (TB) is an infectious airborne disease caused by Mycobacterium tuberculosis. Since the 1990 s, many countries have made significant progress in reducing the incidence of TB and associated mortality by improving health services and strengthening surveillance systems. Nevertheless, due to the emergence of multidrug-resistant TB (MDR-TB), alongside extensively drug-resistant TB (XDR-TB) and TB-HIV co-infection, TB remains one of the lead causes of death arising from infectious disease worldwide, especially in developing countries and disadvantaged populations. Marine natural products (MNPs) have received a large amount of attention in recent years as a source of pharmaceutical constituents and lead compounds, and are expected to offer significant resources and potential in the fields of drug development and biotechnology in the years to come. This review summarizes 169 marine natural products and their synthetic derivatives displaying anti-TB activity from 2013 to the present, including their structures, sources and functions. Partial synthetic information and structure-activity relationships (SARs) are also included.

Identification of heptonic acid γ-lactone by its unusual peracetylated derivative from Amorphophallus paeoniifolius

The methanolic extract of Amorphophallus paeoniifolius was peracetylated to obtain an unusual peracetylated γ-lactone backbone. Structure elucidation revealed that this compound is an outcome of the chemical transformation of heptonic acid γ-lactone.

Aaptamine-rich Fraction from the Indonesian Marine Sponge, Aaptos suberitoides, Exhibits a Cytotoxic Effect on DLD-1 Colorectal Cancer Cells

OBJECTIVE

This study aimed to investigate the cytotoxicity effect of the ethyl acetate extract of Aaptos suberitoides on colorectal cancer cells (DLD-1) and murine fibroblast cells (NIH-3T3).

METHODS

A. suberitoides was collected from Putus Island, Bunaken National Park, North Sulawesi, Indonesia, and was processed with maceration and ethyl acetate extraction. The sponge extract was characterized based on Thin Layer Chromatography (TLC) and then identified by using LCMS/MS analysis. DLD-1 and NIH-3T3 cells were treated with the ethyl acetate extract and then followed by 3- [4, 5-dimethylthiazol-2-yl] -2.5 diphenyl tetrazolium bromide (MTT) assay to assess their cytotoxicity effect.

RESULTS

LCMS/MS analysis showed that the most abundant compounds in this extract were identified as aaptamine (1). Furthermore, this study revealed that the active ethyl acetate fraction of A. suberitoides has cytotoxic effects in colorectal cancer DLD-1 cells with an IC50 value of 9.597 µg/mL, higher than NIH-3T3 cells with an IC50 value of 12.23 µg/mL Thus, the active ethyl acetate fraction of A. suberitoides is considered more toxic to cancer cells than normal cells.

CONCLUSION

This study provides the first evidence to support the role of the ethyl acetate extract of A. suberitoides sponge extracts to be developed as a colorectal anticancer agent.

Total Synthesis of 4-epi-Bengamide E

Bengamide E is a bioactive natural product that was isolated from Jaspidae sponges by Crews and co-workers in 1989. It displays a wide range of biological activities, including antitumor, antibiotic, and anthelmintic properties. With the aim of investigating the structural feature essential for their activity, several total syntheses of Bengamide E and its analogues have been reported in the literature. Nevertheless, no synthesis of the stereoisomer with modification of its configuration at C-4 carbon has been reported so far. Here, we report the first total synthesis of the 4-epi-Bengamide E. Key reactions in the synthesis include a chemoenzimatic desymmetrization of biobased starting materials and a diastereoselective Passerini reaction using a chiral, enantiomerically pure aldehyde, and a lysine-derived novel isocyanide.

Antitumor activity of bengamide ii in a panel of human and murine tumor cell lines: In vitro and in vivo determination of effectiveness against lung cancer

Lung cancer is the most commonly diagnosed cancer and the one that causes the most deaths worldwide, so there is a need for therapies that improve survival rates. Products derived from marine organisms are a source of novel and potent antitumor compounds, but they present the great obstacle of their obtaining from the natural environment and the problems associated with the synthesis and biological effects of chemical analogues. In this work, a Bengamide analogue (Bengamide II) was chemically synthesized and in vitro and in vivo studies were performed to determine its antitumor activity and mechanisms of action. It was shown to have potent antiproliferative activity in lung cancer lines in 2D and 3D models. In addition, Bengamide II-treated cells showed G2/M and G0/G1 cell cycle arrest, together with a decrease in the proliferation marker Ki67. As for the mechanism of action, the treatment was associated with increased LC3-II expression and production of acidic vesicles signaling autophagy. In addition, Bengamide II treatment was associated with caspase-3 activation and DNA fragmentation related to apoptosis. Furthermore, a reduction of VEGFA expression, related to angiogenesis, was also observed. In vivo studies showed that Bengamide II markedly reduced tumor volume and metastases increasing survival. Additionally, it revealed no systemic toxicity in in vivo models at the therapeutic doses used, which is essential for its future clinical use. Taken together, the chemically synthesized bengamide analogue Bengamide II, is a promising drug for lung cancer treatment showing relevant antitumor activity and significant safety.

PARP1 inhibition by Olaparib reduces the lethality of pancreatic cancer cells and increases their sensitivity to Gemcitabine

Pancreatic cancer (PC) is one of the tumors with the lowest survival rates due to the poor efficacy of the treatments currently used. Gemcitabine (GMZ), one of the chemotherapeutic agents employed when the tumor is unresectable, frequently fails due to the development of drug resistance. PARP1 is a relevant protein in this phenomenon and appears to be related to cancer progression in several types of tumors, including PC. To determine the relevance of PARP1 in the development and treatment of PC, we used the Panc02 cell line to generate modified PC cells with stably inhibited PARP1 expression (Panc02-L) and used GMZ, Olaparib (OLA) and GMZ+OLA as therapeutic strategies. Viability, radiosensitization, angiogenesis, migration, colony formation, TUNEL, cell cycle, multicellular tumorsphere induction and in vivo assays were performed to test the influence of PARP1 inhibition on resistance phenomena and tumor progression. We demonstrated that stable inhibition or pharmacological blockade of PARP1 using OLA-sensitized Panc02 cells against GMZ significantly decreased their IC₅₀, reducing colony formation capacity, cell migration and vessel formation (angiogenesis) in vitro. Furthermore, in vivo analyses revealed that Panc02-L-derived (PARP1-inhibited) tumors showed less growth and lethality, and that GMZ+OLA treatment significantly reduced tumor growth. In conclusion, PARP1 inhibition, both alone and in combination with GMZ, enhances the effectiveness of this chemotherapeutic agent and represents a promising strategy for the treatment of PC.

The Development of the Bengamides as New Antibiotics against Drug-Resistant Bacteria

The bengamides comprise an interesting family of natural products isolated from sponges belonging to the prolific Jaspidae family. Their outstanding antitumor properties, coupled with their unique mechanism of action and unprecedented molecular structures, have prompted an intense research activity directed towards their total syntheses, analogue design, and biological evaluations for their development as new anticancer agents. Together with these biological studies in cancer research, in recent years, the bengamides have been identified as potential antibiotics by their impressive biological activities against various drug-resistant bacteria such as Mycobacterium tuberculosis and Staphylococcus aureus. This review reports on the new advances in the chemistry and biology of the bengamides during the last years, paying special attention to their development as promising new antibiotics. Thus, the evolution of the bengamides from their initial exploration as antitumor agents up to their current status as antibiotics is described in detail, highlighting the manifold value of these marine natural products as valid hits in medicinal chemistry.

Integration of transcriptomics and metabolomics reveals anlotinib-induced cytotoxicity in colon cancer cells

BACKGROUND

Mounting evidences suggested that anlotinib exhibits effective anti-tumor activity in various cancer types, such as lung cancer, glioblastoma and medullary thyroid cancer. However, its function in colon cancer remains to be further revealed.

METHODS

Colon cancer cells (HCT-116) were treated with or without anlotinib. Transcript and metabolite data were generated through RNA sequencing and liquid chromatography-tandem mass spectrometry, respectively. The integrated analysis transcriptomics and metabolomics was conducted using R programs and online tools, including ClusterProfiler R program, GSEA, Prognoscan and Cytoscape.

RESULTS

We found that differentially expressed genes (DEGs) were mainly involved in metabolic pathways and ribosome pathway. Structural maintenance of chromosome 3 (SMC3), Topoisomerase II alpha (TOP2A) and Glycogen phosphorylase B (PYGB) are the most significant DEGs which bring poor clinical prognosis in colon cancer. The analysis of metabolomics presented that most of the differentially accumulated metabolites (DAMs) were amino acids, such as L-glutamine, DL-serine and aspartic acid. The joint analysis of DEGs and DAMs showed that they were mainly involved in protein digestion and absorption, ABC transporters, central carbon metabolism, choline metabolism and Gap junction. Anlotinib affected protein synthesis and energy supporting of colon cancer cells by regulating amino acid metabolism.

CONCLUSIONS

Anlotinib has a significant effect on colon cancer in both transcriptome and metabolome. Our research will provide possible targets for colon cancer treatment using anlotinib.