Mononaphthalimide spermidine conjugate induces cell proliferation inhibition and apoptosis in HeLa cells

Common Pathogenetic Mechanisms Underlying Aging and Tumor and Means of Interventions

Recently, there has been an increase in the incidence of malignant tumors among the older population. Moreover, there is an association between aging and cancer. During the process of senescence, the human body suffers from a series of imbalances, which have been shown to further accelerate aging, trigger tumorigenesis, and facilitate cancer progression. Therefore, exploring the junctions of aging and cancer and searching for novel methods to restore the junctions is of great importance to intervene against aging-related cancers. In this review, we have identified the underlying pathogenetic mechanisms of aging-related cancers by comparing alterations in the human body caused by aging and the factors that trigger cancers. We found that the common mechanisms of aging and cancer include cellular senescence, alterations in proteostasis, microbiota disorders (decreased probiotics and increased pernicious bacteria), persistent chronic inflammation, extensive immunosenescence, inordinate energy metabolism, altered material metabolism, endocrine disorders, altered genetic expression, and epigenetic modification. Furthermore, we have proposed that aging and cancer have common means of intervention, including novel uses of common medicine (metformin, resveratrol, and rapamycin), dietary restriction, and artificial microbiota intervention or selectively replenishing scarce metabolites. In addition, we have summarized the research progress of each intervention and revealed their bidirectional effects on cancer progression to compare their reliability and feasibility. Therefore, the study findings provide vital information for advanced research studies on age-related cancers. However, there is a need for further optimization of the described methods and more suitable methods for complicated clinical practices. In conclusion, targeting aging may have potential therapeutic effects on aging-related cancers.

Caspase-independence and characterization of bisnaphthalimidopropyl spermidine induced cytotoxicity in HL60 cells

Bisnaphthalimides are DNA intercalators of potential use as chemotherapeutics but for which the range of mechanism of action is only gradually being elucidated. Using human promyelocytic HL-60 cells, we extend characterization of the cytotoxicity of bisnaphthalimidopropylspermidine (BNIPSpd) and examine the relationship with caspase-activity. Within 4 h exposure, BNIPSpd (1-10 μM) induced significant DNA strand breakage. Evidence of apoptosis was progressive through the experimental period. Within 6 h, BNIPSpd increased the proportion of cells exhibiting plasma membrane phosphatidylserine exposure. Within 12 h, active caspase expression increased and was sustained with 5 and 10 μM BNIPSpd. Flow cytometric analysis revealed caspase activity in cells with and without damaged membranes. By 24 h, 5 and 10 μM BNIPSpd increased hypodiploid DNA content and internucleosomal DNA fragmentation (DNA ladders) typical of the later stages of apoptosis. 1 μM BNIPSpd exposure also increased hypodiploid DNA content by 48 h. Polyamine levels decreased by 24 h BNIPSpd exposure. The pan-caspase inhibitor, z-VAD-fmk, significantly decreased DNA degradation (hypodiploid DNA and DNA ladders) and cytotoxicity. Despite this, cell growth and viability remained significantly impaired. We propose that BNIPSpd cytotoxicity arises through DNA damage and not polyamine depletion and that cytotoxicity is dominated by but not dependent upon caspase driven apoptosis.

Synthesis and evaluation of LOX inhibitory activity of 2-(1,3-Dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)-N-phenylacetamide derivatives

A family of structurally related LOX enzymes present in human cells which catalyse the metabolism of released arachidonic acid from phospholipids by inflammatory stimuli, to biologically active mediators. Mainly, expression of three types of LOXs occurs in cells, which catalyse the insertion of molecular oxygen into the molecule of arachidonic acid at carbon 5, 12, and 15. According to this chemical reaction, the LOXs are named 5-, 12-, and 15-LOX, amongst which, 15-LOX with isoforms 15-LOX-1 and 15-LOX-2 have critical role in neoplastic diseases. 15-LOX-1 is overexpressed in some neoplastic conditions. Hence, in this research, we focused on the synthesis of naphthalimide analogs as potential 15-LOX-1 inhibitors. Fortunately, the most of synthesized compounds demonstrated remarkable inhibitory potency towards 15-LOX-1 in nanomolar ranges. Naphthalimide derivatives could be suggested as potential LOX inhibitors with likely applications of anticancer activity.

Study on the synthesis, biological activity and spectroscopy of naphthalimide-diamine conjugates

Eleven novel naphthalimide-diamine conjugates were synthesized and their structures were confirmed by elemental analysis, 1H-NMR, 13C-NMR and MS. Their in vitro antitumor activities were assessed using MTT assays on two cancerous cell lines K562, HCT116, and one normal hepatoma cell line QSG 7701. Compound 7f exhibited potent antitumor activity on HCT116 cells and favorable cell selectivity toward QSG 7701 compared with the positive control, amonafide. Moreover, 7f could block HeG2 cells in the G2/M phase and induce HeG2 cells apoptosis. The interaction of compound 7f with herring sperm DNA was studied by UV/vis absorption and fluorescence spectroscopy under physiological conditions (pH = 7.4). The observed spectral quenching of compound 7f by DNA and the displacement of EB from DNA-EB complex by compound 7f indicated that compound 7f could intercalate into DNA base pairs, which was also corroborated by the effect of KI on compound-DNA interaction. Further caloric fluorescent tests revealed that the quenching mechanism was a static type. Meanwhile, the binding constants, thermodynamic parameters and the effect of NaCl on compound-DNA interaction showed that the type of interaction force was mainly hydrogen bonds and the binding process was driven by hydrogen and van der Waals bonding.

The influence of bisnaphthalimidopropyl polyamines on DNA instability and repair in Caco-2 colon epithelial cells

Bisnaphthalimido compounds bis-intercalate to DNA via the major groove and are potentially potent cancer therapeutics. Previously, we incorporated natural polyamines as linkers connecting the two naphthalimido ring moieties to create a series of soluble bisnaphthalimidopropyl polyamines (BNIPPs). Here, extending earlier work on bisnaphthalimidopropylspermidine (BNIPSpd)-induced apoptosis in colon adenocarcinoma Caco-2 cells, we compare the cytotoxicity and genotoxicity of BNIPSpd relative to the spermine and oxaspermine derivatives, bisnaphthalimidopropylspermine (BNIPSpm) and bisnaphthalimidopropyloxaspermine (BNIPOSpm). The order of cytotoxicity after 24 h was BNIPSpd (IC(50) = 0.47 μM) > BNIPSpm (IC(50) = 10.04 μM) > BNIPOSpm (IC(50) >50 μM). After a 72-h BNIPOSpm exposure, an IC(50) = 10.25 μM was achieved. With 4-h exposure to BNIPSpd or BNIPSpm or 12-h exposure to BNIPOSpm, concentrations ≥1 μM induced a significant dose-dependent increase in DNA damage as measured by alkaline single-cell gel electrophoresis. The longer incubation times required for BNIPOSpm to induce DNA strand breaks reflect a slower rate of BNIPOSpm cellular distribution as monitored via BNIPP fluorescence within the cells. Moreover, exposure to a non-genotoxic concentration of BNIPSpd, BNIPSpm (0.1 μM for 4 h) or BNIPOSpm (0.1 μM for 12 h) induced a significant decrease in repair of oxidative DNA damage induced by hydrogen peroxide. In conclusion, BNIPP exposure in Caco-2 cells is associated with significant induction of DNA damage and inhibition of DNA repair at non-genotoxic concentrations. The latter is a novel consequence of BNIPP-cell interactions which adds to the spectrum of therapeutically relevant activities that may be exploited for the design and development of naphthalimide-based therapeutics.