Effect of camptothecin on inducible nitric oxide synthase expression in the colon cancer SW480 cell line

Gasotransmitters in the tumor microenvironment: Impacts on cancer chemotherapy (Review)

Nitric oxide, carbon monoxide and hydrogen sulfide are three endogenous gasotransmitters that serve a role in regulating normal and pathological cellular activities. They can stimulate or inhibit cancer cell proliferation and invasion, as well as interfere with cancer cell responses to drug treatments. Understanding the molecular pathways governing the interactions between these gases and the tumor microenvironment can be utilized for the identification of a novel technique to disrupt cancer cell interactions and may contribute to the conception of effective and safe cancer therapy strategies. The present review discusses the effects of these gases in modulating the action of chemotherapies, as well as prospective pharmacological and therapeutic interfering approaches. A deeper knowledge of the mechanisms that underpin the cellular and pharmacological effects, as well as interactions, of each of the three gases could pave the way for therapeutic treatments and translational research.

Camptothecin Encapsulated in β-Cyclodextrin-EDTA-Fe3O4 Nanoparticles Induce Metabolic Reprogramming Repair in HT29 Cancer Cells through Epigenetic Modulation: A Bioinformatics Approach

Cancer progresses through a distinctive reprogramming of metabolic pathways directed by genetic and epigenetic modifications. The hardwired changes induced by genetic mutations are resilient, while epigenetic modifications are softwired and more vulnerable to therapeutic intervention. Colon cancer is no different. This gives us the need to explore the mechanism as an attractive therapeutic target to combat colon cancer cells. We have previously established the enhanced therapeutic efficacy of a newly formulated camptothecin encapsulated in β-cyclodextrin-EDTA-Fe₃O₄ nanoparticles (CPT-CEF) in colon cancer cells. We furthered this study by carrying out RNA sequencing (RNA-seq) to underscore specific regulatory signatures in the CPT-CEF treated versus untreated HT29 cells. In the study, we identified 95 upregulated and 146 downregulated genes spanning cellular components and molecular and metabolic functions. We carried out extensive bioinformatics analysis to harness genes potentially involved in epigenetic modulation as either the cause or effect of metabolic rewiring exerted by CPT-CEF. Significant downregulation of 13 genes involved in the epigenetic modulation and 40 genes from core metabolism was identified. Three genes, namely, DNMT-1, POLE3, and PKM-2, were identified as the regulatory overlap between epigenetic drivers and metabolic reprogramming in HT29 cells. Based on our results, we propose a possible mechanism that intercepts the two functional axes, namely epigenetic control, and metabolic modulation via CPT-CEF in colon cancer cells, which could skew cancer-induced metabolic deregulation towards metabolic repair. Thus, the study provides avenues for further validation of transcriptomic changes affected by these deregulated genes at epigenetic level, and ultimately may be harnessed as targets for regenerating normal metabolism in colon cancer with better treatment potential, thereby providing new avenues for colon cancer therapy.

Photophysical and thermodynamic evaluation on the in vitro and in silico binding profile of Camptothecin with DNA

Camptothecin (CMT) is an anti-tumour alkaloid drug exhibiting selective topoisomerase-I inhibitory activity by eventually hindering dynamic functions of DNA duplex via initiating apoptosis. Unravelling the binding mechanism of CMT with bio macromolecular systems can offer fundamental information regarding the mechanism of actions which can lead to the design of rational proactive drugs. This study endeavoured the binding interactions of CMT with calf thymus DNA (ct-DNA) along with the structural alterations attained by the DNA duplex owing to CMT interactions through multi-spectroscopic, calorimetric and molecular docking studies. The UV-visible absorbance and fluorescence quenching studies revealed the binding strength of CMT with ct-DNA, evident from the binding constants K₁ = 3.79 × 10³ M^-1 and Kq = 2 × 10³ M^-1. The time-resolved lifetime measurements inferred that the quenching was static due to the non-fluorescent ground state complex formation. The dye displacement study, temperature melting and viscosity measurements established a typical non-intercalative binding mode of CMT with ct-DNA. The binding isotherm deduced from ITC was found to be spontaneous and exothermic exerting a promising ΔG value of -6.2 kcal mol^-1. The thermal kinetic parameters implied that the forces primarily involved in the CMT-ct-DNA complexation are hydrogen bonding and van der Waals interactions. Moreover, the structural alterations of DNA duplex reflected in the CD and FTIR spectra could undeniably confirm the groove binding manner of CMT. The in silico extra precision docking study explored more accurate molecular illustrations of sequence specific minor groove binding mechanism evolved between CMT and DNA corroborating well with the experimental results. These innovative findings may shorten the path towards the development of novel and more effective CMT drug derivatives.

Inverse Association between Glucose‒6‒Phosphate Dehydrogenase Deficiency and Hepatocellular Carcinoma

Background:

Studies in experimental models and humans suggest that glucose-6-phosphate dehydrogenase (G6PD) deficiency, an inherited condition, may be inversely related to hepatocellular carcinoma (HCC). We tested this hypothesis in a large cohort of Sardinian patients.

Methods:

A case-control study was performed using data from 11,143 records of patients who underwent upper endoscopy between 2002 and 2017. Gender, age, G6PD status and information regarding the presence of HCC, were recorded. Cases (HCC positive) and controls (HCC negative) were compared for the presence of G6PD deficiency adjusting for major HCC risk factors using logistic regression.

Results:

Overall, 114 HCC cases and 11,029 controls were identified. G6PD deficiency was detected in 11.5% of study participants, and was associated with a reduced risk of HCC [odds ratio (OR); 0.451; 95% confidence interval (CI), 0.207−0.982] after adjusting for all covariates. Factors significantly associated with HCC were cirrhosis (OR, 23.30; 95% CI, 11.48−47.25), diabetes (OR, 2.396; 95% CI, 1.449−3.963), among infection hepatitis HBV with an OR of 2.326, age ≥65 years (OR, 1.941; 95% CI, 1.234−2.581) and male gender (OR, 1.611; 95% CI, 1.006−3.081).

Conclusions:

Our study revealed a significant inverse association between G6PD deficiency and risk of HCC. These findings need to be confirmed in further studies.

Efficiency of newly formulated camptothecin with β-cyclodextrin-EDTA-Fe3O4 nanoparticle-conjugated nanocarriers as an anti-colon cancer (HT29) drug

Camptothecin (CPT) is an anti-cancer drug that effectively treats various cancers, including colon cancer. However, poor solubility and other drawbacks have restricted its chemotherapeutic potential. To overcome these restrictions, CPT was encapsulated in CEF (cyclodextrin-EDTA-FE₃O₄), a composite nanoparticle of magnetic iron oxide (Fe₃O₄), and β-cyclodextrin was cross-linked with ethylenediaminetetraacetic acid (EDTA). This formulation improved CPT’s solubility and bioavailability for cancer cells. The use of magnetically responsive anti-cancer formulation is highly advantageous in cancer chemotherapy. The chemical characterisation of CPT-CEF was studied here. The ability of this nano-compound to induce apoptosis in HT29 colon cancer cells and A549 lung cancer cells was evaluated. The dose-dependent cytotoxicity of CPT-CEF was shown using MTT. Propidium iodide and Annexin V staining, mitochondrial membrane depolarisation (JC-1 dye), and caspase-3 activity were assayed to detect apoptosis in CPT-CEF-treated cancer cells. Cell cycle analysis also showed G1 phase arrest, which indicated possible synergistic effects of the nano-carrier. These study results show that CPT-CEF causes a dose-dependent cell viability reduction in HT29 and A549 cells and induces apoptosis in colon cancer cells via caspase-3 activation. These data strongly suggest that CPT could be used as a major nanocarrier for CPT to effectively treat colon cancer.

Glucose-6-phosphate dehydrogenase deficiency and risk of colorectal cancer in Northern Sardinia: A retrospective observational study

Glucose-6-phosphate dehydrogenase (G6PD) deficiency has been associated with a lower cancer risk, possibly via a reduction of mutagenic oxygen-free radicals and by reducing nicotinamide-adeninedinucleotide-phosphate for replicating cells. In Sardinia, the enzyme defect is frequent as a consequence of selection by malaria in the past. This study investigated the relationship between G6PD deficiency and colorectal cancer (CRC).A retrospective case-control study of 3901 patients from Sardinia, who underwent a colonoscopy between 2006 and 2016, was performed. G6PD phenotype was assessed for each subject. The proportion of pre and malignant colorectal lesions was compared in cases (G6PD-deficient) and controls (G6PD-normal). Data concerning age, sex, family history of CRC, smoking habits, body height, and weight, and also associated diseases were collected.The CRC risk reduction was 43.2% among G6PD-deficient compared with G6PD-normal subjects (odds ratio 0.57, 95% confidence interval 0.37-0.87, P = 0.010). Age, sex, family history of CRC, and also comorbidities such as type 1 diabetes and ischemic heart disease, were significantly associated with CRC risk. The protective effect of G6PD deficiency remained significant after adjusting for all covariates by logistic regression analysis, and was consistently lower across all age groups.Glucose-6-phosphate dehydrogenase enzyme deficiency is associated with a reduced risk of CRC.