Elevated N1-Acetylspermidine Levels in Doxorubicin-treated MCF-7 Cancer Cells: Histone Deacetylase 10 Inhibition with an N1-Acetylspermidine Mimetic.

Cancer drug resistance is associated with metabolic adaptation. Cancer cells have been shown to implicate acetylated polyamines in adaptations during cell death. However, exploring the mimetic of acetylated polyamines as a potential anticancer drug is lacking. We performed intracellular metabolite profiling of human breast cancer MCF-7 cells treated with doxorubicin (DOX), a well known anticancer drug. A novel and in-house vertical tube gel electrophoresis assisted procedure followed by LC-HRMS analysis was employed to detect acetylated polyamines such as N1-acetylspermidine. We designed a mimetic N1-acetylspermidine (MINAS) which is a known substrate of histone deacetylase 10 (HDAC10). Molecular docking and molecular dynamics (MDs) simulations were used to evaluate the inhibitory potential of MINAS against HDAC10. The inhibitory potential and the ADMET profile of MINAS were compared to a known HDAC10 inhibitor Tubastatin A. N1-acetylspermidine, an acetylated form of polyamine, was detected intracellularly in MCF-7 cells treated with DOX over DMSO-treated MCF-7 cells. We designed and curated MINAS (PubChem CID 162679241). Molecular docking and MD simulations suggested the strong and comparable inhibitory potential of MINAS (-8.2 kcal/mol) to Tubastatin A (-8.4 kcal/mol). MINAS and Tubastatin A share similar binding sites on HDAC10, including Ser138, Ser140, Tyr183, and Cys184. Additionally, MINAS has a better ADMET profile compared to Tubastatin A, with a high MRTD value and lower toxicity. In conclusion, the data show that N1-acetylspermidine levels rise during DOX-induced breast cancer cell death. Additionally, MINAS, an N1-acetylspermidine mimetic compound, could be investigated as a potential anticancer drug when combined with chemotherapy like DOX.

Secretion of Sphinganine by Drug-Induced Cancer Cells and Modified Mimetic Sphinganine (MMS) as c-Src Kinase Inhibitor.

BACKGROUND: Cancer cells exhibit selective metabolic reprogramming to promote proliferation, invasiveness, and metastasis. Sphingolipids such as sphingosine and sphinganine have been reported to modulate cell death processes in cancer cells. However, the potential of extracellular sphinganine and its mimetic compounds as inducers of cancer cell death has not been thoroughly investigated. METHODS: We obtained extracellular conditioned medium from HCT-116 cells treated with the previously reported anticancer composition, goat urine DMSO fraction (GUDF). The extracellular metabolites were purified using a novel and in-house developed vertical tube gel electrophoresis (VTGE) technique and identified through LC-HRMS. Extracellular metabolites such as sphinganine, sphingosine, C16 sphinganine, and phytosphingosine were screened for their inhibitory role against intracellular kinases using molecular docking. Molecular dynamics (MD) simulations were performed to study the inhibitory potential of a novel designed modified mimetic sphinganine (MMS) (Pubchem CID: 162625115) upon c-Src kinase. Furthermore, inhibitory potential and ADME profile of MMS was compared with luteolin, a known c-Src kinase inhibitor. RESULTS: Data showed accumulation of sphinganine and other sphingolipids such as C16 sphinganine, phytosphingosine, and ceramide (d18:1/14:0) in the extracellular compartment of GUDF-treated HCT-116 cells. Molecular docking projected c-Src kinase as an inhibitory target of sphinganine. MD simulations projected MMS with strong (-7.1 kcal/mol) and specific (MET341, ASP404) binding to the inhibitory pocket of c-Src kinase. The projected MMS showed comparable inhibitory role and acceptable ADME profile over known inhibitors. CONCLUSION: In summary, our findings highlight the significance of extracellular sphinganine and other sphingolipids, including C16 sphinganine, phytosphingosine, and ceramide (d18:1/14:0), in the context of drug-induced cell death in HCT-116 cancer cells. Furthermore, we demonstrated the importance of extracellular sphinganine and its modified mimetic sphinganine (MMS) as a potential inhibitor of c-Src kinase. These findings suggest that MMS holds promise for future applications in targeted and combinatorial anticancer therapy.

Understanding Cancer's Defense against Topoisomerase-Active Drugs: A Comprehensive Review.

In recent years, the emergence of cancer drug resistance has been one of the crucial tumor hallmarks that are supported by the level of genetic heterogeneity and complexities at cellular levels. Oxidative stress, immune evasion, metabolic reprogramming, overexpression of ABC transporters, and stemness are among the several key contributing molecular and cellular response mechanisms. Topo-active drugs, e.g., doxorubicin and topotecan, are clinically active and are utilized extensively against a wide variety of human tumors and often result in the development of resistance and failure to therapy. Thus, there is an urgent need for an incremental and comprehensive understanding of mechanisms of cancer drug resistance specifically in the context of topo-active drugs. This review delves into the intricate mechanistic aspects of these intracellular and extracellular topo-active drug resistance mechanisms and explores the use of potential combinatorial approaches by utilizing various topo-active drugs and inhibitors of pathways involved in drug resistance. We believe that this review will help guide basic scientists, pre-clinicians, clinicians, and policymakers toward holistic and interdisciplinary strategies that transcend resistance, renewing optimism in the ongoing battle against cancer.

Organic Acids Derived from Saliva-amalgamated Betel Quid Filtrate Are Predicted as a Ten-eleven Translocation-2 Inhibitor.

There is a lack of evidence regarding the use of betel quid (BQ) and its potential contribution to oral cancer. Limited attention has been directed towards investigating the involvement of BQ-derived organic acids in the modulation of metabolic-epigenomic pathways associated with oral cancer initiation and progression. We employed novel protocol for preparing saliva-amalgamated BQ filtrate (SABFI) that mimics the oral cavity environment. SABFI and saliva control were further purified by an in-house developed vertical tube gel electrophoresis tool. The purified SABFI was then subjected to liquid chromatography-high resolution mass spectrometry analysis to identify the presence of organic acids. Profiling of SABFI showed a pool of prominent organic acids such as citric acid. malic acid, fumaric acid, 2-methylcitric acid, 2-hydroxyglutarate, cis-aconitic acid, succinic acid, 2-hydroxyglutaric acid lactone, tartaric acid and ß-ketoglutaric acid. SABFI showed anti-proliferative and early apoptosis effects in oral cancer cells. Molecular docking and molecular dynamics simulations predicted that SABFI-derived organic acids as potential inhibitors of the epigenetic demethylase enzyme, Ten-Eleven Translocation-2 (TET2). By binding to the active site of α-ketoglutarate, a known substrate of TET2, these organic acids are likely to act as competitive inhibitors. This study reports a novel approach to study SABFI-derived organic acids that could mimic the chemical composition of BQ in the oral cavity. These SABFI-derived organic acids projected as inhibitors of TET2 and could be explored for their role oral cancer.

Reduced Level of Prolylhydroxyproline in the Nail Clippings of Oral Cancer Patients and its Role as an Activator of Phospholipase C-ß2.

BACKGROUND: The oral cancer microenvironment plays an important role in the development and progression of the disease which depicts the heterogeneous nature of diseases. Several cellular and non-cellular factors, including dipeptides, have been reported to drive tumor progression and metastasis. Among various secreted molecules in the tumor microenvironment, prolylhydroxyproline (Pro-Hyp) is a collagen-degraded product with specific relevance to fibrosis and oral cancer. However, the detection of Pro-Hyp in the nails of oral cancer patients is a potential biomarker, and our understanding of the biological relevance of Pro-Hyp is highly limited. METHODS: Here, the authors have attempted to use a novel and in-house vertical tube gel electrophoresis (VTGE) protocol to evaluate the level of Pro-Hyp in the nails of oral cancer patients and healthy subjects. Furthermore, we employed molecular docking and molecular dynamics (MD) simulations to predict the biological function of Pro-Hyp. ADME profiles such as the druglikeness and leadlikeness of Pro-Hyp and a known PLC-ß2 activator, m-3M3FBS, were evaluated by the SWISS-ADME server. RESULTS: We report that among various key metabolites, Pro-Hyp, a dipeptide, is reduced in the nails of oral cancer patients. Molecular docking and MD simulations helped to suggest the potential role of Pro-Hyp as an activator of Phospholipase C-ß2 (PLC-ß2). Pro-Hyp displayed good binding affinity (-7.6 kcal/mol) with specific interactions by a conventional hydrogen bond with key residues, such as HIS311, HIS312, VAL641, and GLU743. MD simulations showed that the activator binding residues and stability of complexes are similar to the well-known activator m-3M3FBS of PLC-ß2. ADME profiles such as the druglikeness and leadlikeness of Pro-Hyp were found to be highly comparable and even better than those of m-3M3FBS. CONCLUSION: This study is one of the first reports on Pro-Hyp as a metabolite biomarker in the nails of oral cancer patients. Furthermore, the implications of Pro-Hyp are proposed to activate PLC-ß2 as a pro-tumor signaling cascade. In the future, diagnostic and therapeutic approaches may be explored as biomarkers and mimetic of Pro-Hyp.