Vitamin E succinate exerts anti-tumour effects on human cervical cancer cells via the CD47-SIRPɑ pathway both in vivo and in vitro

Research Progress of SN38 Drug Delivery System in Cancer Treatment

The active metabolite of irinotecan (CPT-11), 7-ethyl-10-hydroxycamptothecin (SN38), is 100-1000 times more active than CPT-11 and has shown inhibitory effects on a range of cancer cells, including those from the rectal, small cell lung, breast, esophageal, uterine, and ovarian malignancies. Despite SN38's potent anticancer properties, its hydrophobicity and pH instability have caused substantial side effects and anticancer activity loss, which make it difficult to use in clinical settings. To solve the above problems, the construction of SN38-based drug delivery systems is one of the most feasible methods to improve drug solubility, enhance drug stability, increase drug targeting ability, improve drug bioavailability, enhance therapeutic efficacy and reduce adverse drug reactions. Therefore, based on the targeting mechanism of drug delivery systems, this paper reviews SN38 drug delivery systems, including polymeric micelles, liposomal nanoparticles, polymeric nanoparticles, protein nanoparticles, conjugated drug delivery systems targeted by aptamers and ligands, antibody-drug couplings, magnetic targeting, photosensitive targeting, redox-sensitive and multi-stimulus-responsive drug delivery systems, and co-loaded drug delivery systems. The focus of this review is on nanocarrier-based SN38 drug delivery systems. We hope to provide a reference for the clinical translation and application of novel SN38 medications.

Discovery of Alpha-Tocopheryl Succinate as a Cancer Treatment Agent Led to the Development of Methods to Potentially Improve the Efficacy of Cancer Therapy

The discovery of alpha-tocopheryl succinate (alpha-TS) as a cancer therapeutic agent markedly stimulated research with or without tumor therapeutic agents on cancer cells and normal cells. Results showed that alpha-TS treatment induced apoptosis in cancer cells and enhanced the apoptotic effects of tumor therapeutic agents on tumor cells in a synergistic manner without affecting the growth of normal cells. Liposomal alpha-TS was more effective than alpha-TS. Some tumors are difficult to treat with chemotherapeutic agents while some become resistant of such treatment. Using a nanotechnology technique, it was demonstrated that alpha-TS conjugated with a chemotherapeutic agent enhanced the levels of apoptosis and restored the sensitivity of tumor cells to that chemotherapeutic agent. The mechanisms of action of alpha-TS alone or in combination with therapeutic agents include the following: (a) inhibition of the expression of oncogenes C-myc and H-ras; (b) alterations in the levels of expression of numerous genes; (c) activation of caspases; (d) inhibition of angiogenesis; (e) destabilization of mitochondria and lysosomes; (f) inhibition of production of production of prostaglandin E2 (PGE2) and PGE2-mediated pro-inflammatory responses; (g) reduction of survivin signaling pathway; and (h) reduction of CD47 expression on the tumor cell surface causing enhancement of phagocytic activity of macrophages leading to engulfment of tumor cells. Despite impressive results in cell culture and in animal models, no studies with alpha-TS alone or in combination with cancer therapeutic agents in human cancer resistant to these therapies have been performed.

The role of miR1 and miR133a in new-onset atrial fibrillation after acute myocardial infarction

BACKGROUND

The development of new-onset atrial fibrillation (NOAF) after acute myocardial infarction (AMI) is a clinical complication that requires a better understanding of the causative risk factors. This study aimed to explore the risk factors and the expression and function of miR-1 and miR-133a in new atrial fibrillation after AMI.

METHODS

We collected clinical data from 172 patients with AMI treated with emergency percutaneous coronary intervention (PCI) between October 2021 and October 2022. Independent predictors of NOAF were determined using binary logistic univariate and multivariate regression analyses. The predictive value of NOAF was assessed using the area under the receiver operating characteristic (ROC) curve for related risk factors. In total, 172 venous blood samples were collected preoperatively and on the first day postoperatively; the expression levels of miR-1 and miR-133a were determined using the polymerase chain reaction. The clinical significance of miR-1 and miR-133a expression levels was determined by Spearman correlation analysis.

RESULTS

The Glasgow prognostic score, left atrial diameter, and infarct area were significant independent risk factors for NOAF after AMI. We observed that the expression levels of miR-1 and miR-133a were significantly higher in the NOAF group than in the non-NOAF group. On postoperative day 1, strong associations were found between miR-133a expression levels and the neutrophil ratio and between miR-1 expression levels and an increased left atrial diameter.

CONCLUSIONS

Our findings indicate that the mechanism of NOAF after AMI may include an inflammatory response associated with an increased miR-1-related mechanism. Conversely, miR-133a could play a protective role in this clinical condition.

Radixin modulates the plasma membrane localization of CD47 in human uterine cervical adenocarcinoma cells

Despite the dramatic success of immune checkpoint blockers in treating numerous cancer cell types, current therapeutic modalities provide clinical benefits to a subset of patients with cervical cancers. CD47 is commonly overexpressed in a broad variety of cancer cells, correlates with poor clinical prognosis, and acts as a dominant macrophage checkpoint by interacting with receptors expressed on macrophages. It allows cancer cells to escape from the innate immune system and hence is a potential therapeutic target for developing novel macrophage checkpoint blockade immunotherapies. As the intracellular scaffold proteins, ezrin/radixin/moesin (ERM) family proteins post-translationally regulate the cellular membrane localization of numerous transmembrane proteins, by crosslinking them with the actin cytoskeleton. We demonstrated that radixin modulates the plasma membrane localization and functionality of CD47 in HeLa cells. Immunofluorescence analysis and co-immunoprecipitation assay using anti-CD47 antibody showed the colocalization of CD47 and all three ERM families in the plasma membrane, and the molecular interactions between CD47 and all three ERM. Interestingly, gene silencing of only radixin, reduced the CD47 plasma membrane localization and functionality by means of flow cytometry and phagocytosis assay but had little influence on its mRNA expression. Together, in HeLa cells radixin may function as a principal scaffold protein responsible for the CD47 plasma membrane localization.

Attenuated Salmonella carrying plasmid co-expressing HPV16 L1 and siRNA-E6 for cervical cancer therapy

Human papillomavirus (HPV) infection is the major etiological factor for cervical cancer. HPV prophylactic vaccines based on L1 virus-like particles have been considered as an effective prevention method. However, existing recombination vaccines are too expensive for developing countries. DNA vaccines might be a lower-cost and effective alternative. In this study, a plasmid (pcDNA3.1-HPV16-L1) and a co-expressing plasmid (pcDNA3.1-HPV16-L1-siE6) carried by attenuated Salmonella were constructed and their prevention and treatment effect on cervical cancer were observed, respectively. The results showed that pcDNA3.1-HPV16-L1 carried by attenuated Salmonella could induce the production of HPV16-L1 antibodies, IL-2 and INF-γ in mice serum, which presented its prevention effect on HPV. Subsequently, E6 and E7 gene silencing by pCG-siE6 inhibited the growth of cervical cancer both in vitro and in vivo. Furthermore, L1 up-regulation and E6/E7 down-regulation caused by co-expressing plasmid (pcDNA3.1-HPV16-L1-siE6) contributed to a significant anti-tumor effect on the mice. This study suggests that pcDNA3.1-HPV16-L1-siE6 carried by attenuated Salmonella has a synergistic effect of immune regulation and RNA interference in cervical cancer treatment.