p53-dependent apoptosis is essential for the antitumor effect of paclitaxel response to DNA damage in papillary thyroid carcinoma

Twenty years of Gendicine® rAd-p53 cancer gene therapy: The first-in-class human cancer gene therapy in the era of personalized oncology

Genetic mutations in TP53 contribute to human malignancies through various means. To date, there have been a variety of therapeutic strategies targeting p53, including gene therapy to restore normal p53 function, mutant p53 rescue, inhibiting the MDM2-p53 interaction, p53-based vaccines, and a number of other approaches. This review focuses on the functions of TP53 and discusses the aberrant roles of mutant p53 in various types of cancer. Recombinant human p53 adenovirus, trademarked as Gendicine, which is the first anti-tumor gene therapy drug, has made tremendous progress in cancer gene therapy. We herein discuss the biological mechanisms by which Gendicine exerts its effects and describe the clinical responses reported in clinical trials. Notably, the clinical studies suggest that the combination of Gendicine with chemotherapy and/or radiotherapy may produce more pronounced efficacy in slowing tumor growth and progression than gene therapy/chemotherapy alone. Finally, we summarize the methods of administration of recombinant human p53 adenovirus for different cancer types to provide a reference for future clinical trials.

Drug resistance‑related gene targets and molecular mechanisms in the A2780/Taxol‑resistant epithelial ovarian cancer cell line

Epithelial ovarian cancer (EOC) is a fatal gynecological malignant tumor with a low 5-year survival rate. The use of the first-line chemotherapeutic drug, paclitaxel, for the treatment of EOC is associated with resistance, often leading to treatment failure. The present study investigated the gene targets in an A2780 paclitaxel-resistant EOC cell line (A2780/Taxol), and the potential underlying mechanisms using transcriptome sequencing technology and bioinformatics analysis. The transcriptome of the A2780/Taxol cell line was sequenced, and 498 differentially expressed genes were obtained contained in the Gene Expression Omnibus dataset. Further bioinformatics analysis revealed that matrix metalloproteinase 1 (MMP1), zyxin (ZYX) and Unc-5 netrin receptor C (UNC5C) may be gene targets related to paclitaxel resistance. Moreover, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that a potential mechanism associated with paclitaxel resistance was related to cell migration. Furthermore, the expression levels of MMP1, ZYX and UNC5C were verified using western blotting, immunofluorescence and immunohistochemistry in vitro. The results revealed that the expression levels of MMP1 and ZYX were significantly increased in A2780/Taxol cells, while UNC5C expression was significantly decreased, which was consistent with the results of the transcriptome sequencing. The present study demonstrated that MMP1, ZYX and UNC5C may be the gene targets associated with paclitaxel resistance in EOC. These genes have potential to be used as molecular markers for EOC drug therapy, targeted elimination of drug resistance, and evaluation of treatment efficacy and patient prognosis.

Hinokitiol Inhibits Breast Cancer Cells In Vitro Stemness-Progression and Self-Renewal with Apoptosis and Autophagy Modulation via the CD44/Nanog/SOX2/Oct4 Pathway

Breast cancer (BC) represents one of the most prevalent malignant threats to women globally. Tumor relapse or metastasis is facilitated by BC stemness progression, contributing to tumorigenicity. Therefore, comprehending the characteristics of stemness progression and the underlying molecular mechanisms is pivotal for BC advancement. Hinokitiol (β-thujaplicin), a tropolone-related compound abundant in the heartwood of cupressaceous plants, exhibits antimicrobial activity. In our study, we employed three BC cell lines (MDA-MB-231, MCF-7, and T47D) to assess the expression of stemness-, apoptosis-, and autophagy-related proteins. Hinokitiol significantly reduced the viability of cancer cells in a dose-dependent manner. Furthermore, we observed that hinokitiol enhances apoptosis by increasing the levels of cleaved poly-ADP-ribose polymerase (PARP) and phospho-p53. It also induces dysfunction in autophagy through the upregulation of LC3B and p62 protein expression. Additionally, hinokitiol significantly suppressed the number and diameter of cancer cell line spheres by reducing the expression of cluster of differentiation44 (CD44) and key transcription factors. These findings underscore hinokitiol's potential as a therapeutic agent for breast cancer, particularly as a stemness-progression inhibitor. Further research and clinical studies are warranted to explore the full therapeutic potential of hinokitiol in the treatment of breast cancer.

Regulation of Tumor Apoptosis of Poriae cutis-Derived Lanostane Triterpenes by AKT/PI3K and MAPK Signaling Pathways In Vitro

Poria cocos is traditionally used as both food and medicine. Triterpenoids in Poria cocos have a wide range of pharmacological activities, such as diuretic, sedative and tonic properties. In this study, the anti-tumor activities of poricoic acid A (PAA) and poricoic acid B (PAB), purified by high-speed counter-current chromatography, as well as their mechanisms and signaling pathways, were investigated using a HepG2 cell model. After treatment with PAA and PAB on HepG2 cells, the apoptosis was obviously increased (p < 0.05), and the cell cycle arrested in the G2/M phase. Studies showed that PAA and PAB can also inhibit the occurrence and development of tumor cells by stimulating the generation of ROS in tumor cells and inhibiting tumor migration and invasion. Combined Polymerase Chain Reaction and computer simulation of molecular docking were employed to explore the mechanism of tumor proliferation inhibition by PAA and PAB. By interfering with phosphatidylinositol-3-kinase/protein kinase B, Mitogen-activated protein kinases and p53 signaling pathways; and further affecting the expression of downstream caspases; matrix metalloproteinase family, cyclin-dependent kinase -cyclin, Intercellular adhesion molecules-1, Vascular Cell Adhesion Molecule-1 and Cyclooxygenase -2, may be responsible for their anti-tumor activity. Overall, the results suggested that PAA and PAB induced apoptosis, halted the cell cycle, and inhibited tumor migration and invasion through multi-pathway interactions, which may serve as a potential therapeutic agent against cancer.

Enhancing Efficacy of Albumin-Bound Paclitaxel for Human Lung and Colorectal Cancers through Autophagy Receptor Sequestosome 1 (SQSTM1)/p62-Mediated Nanodrug Delivery and Cancer therapy

Selective autophagy is a defense mechanism by which foreign pathogens and abnormal substances are processed to maintain cellular homeostasis. Sequestosome 1 (SQSTM1)/p62, a vital selective autophagy receptor, recruits ubiquitinated cargo to form autophagosomes for lysosomal degradation. Nab-PTX is an albumin-bound paclitaxel nanoparticle used in clinical cancer therapy. However, the role of SQSTM1 in regulating the delivery and efficacy of nanodrugs remains unclear. Here we showed that SQSTM1 plays a crucial role in Nab-PTX drug delivery and efficacy in human lung and colorectal cancers. Nab-PTX induces SQSTM1 phosphorylation at Ser403, which facilitates its incorporation into the selective autophagy of nanoparticles, known as nanoparticulophagy. Nab-PTX increased LC3-II protein expression, which triggered autophagosome formation. SQSTM1 enhanced Nab-PTX recognition to form autophagosomes, which were delivered to lysosomes for albumin degradation, thereby releasing PTX to induce mitotic catastrophe and apoptosis. Knockout of SQSTM1 downregulated Nab-PTX-induced mitotic catastrophe, apoptosis, and tumor inhibition in vitro and in vivo and inhibited Nab-PTX-induced caspase 3 activation via a p53-independent pathway. Ectopic expression of SQSTM1 by transfection of an SQSTM1-GFP vector restored the drug efficacy of Nab-PTX. Importantly, SQSTM1 is highly expressed in advanced lung and colorectal tumors and is associated with poor overall survival in clinical patients. Targeting SQSTM1 may provide an important strategy to improve nanodrug efficacy in clinical cancer therapy. This study demonstrates the enhanced efficacy of Nab-PTX for human lung and colorectal cancers via SQSTM1-mediated nanodrug delivery.

SNRPB promotes cell cycle progression in thyroid carcinoma via inhibiting p53

Papillary thyroid carcinoma (PTC) accounts for more than 80% of all thyroid carcinoma cases. Small nuclear ribonucleoprotein polypeptides B and B1 (SNRPB) has been indicated to be carcinogenic in several cancers; however, its function and mechanism in PTC are unclarified. Real time quantitative polymerase chain reaction and western blotting revealed the upregulation of SNRPB and downregulation of tumor protein p53 in PTC tissues compared with the normal tissues. Flow cytometry and western blotting displayed that SNRPB silencing induced cell cycle arrest at G1 phase and suppressed the expression levels of Cyclin family proteins in PTC cells. In vivo experiments suggested that SNRPB silencing inhibited PTC tumor growth in mice. Bioinformatics analysis revealed that the expression of SNRPB and cell cycle-associated genes in thyroid carcinoma tissues is positively correlated. Immunofluorescence staining and co-immunoprecipitation demonstrated that SNRPB directly interacted with p53 and suppressed its expression in PTC cells. In conclusion, SNRPB facilitates cell cycle progression in PTC by inhibiting p53 expression.

EZH2 affects malignant progression and DNA damage repair of lung adenocarcinoma cells by regulating RAI2 expression

BACKGROUND

Lung adenocarcinoma (LUAD) is featured in high morbidity and mortality. Aberrant activation of the histone methyltransferase EZH2 has close association with cancer progression. This research aimed to deeply dive into the role and possible molecular mechanisms of EZH2 and its downstream genes in malignant progression and DNA damage repair of LUAD cells.

METHODS

Expression of EZH2 in LUAD cells was analyzed by qRT-PCR, and the effects of EZH2 on proliferation, and apoptosis of LUAD cells were examined by CCK-8, colony formation and flow cytometry assays. The downstream targets of EZH2 were predicted by bioinformatics analysis. Then, the targeting relationship between EZH2 and RAI2 was examined by CHIP and luciferase reporter assays. Rescue assay were used to further validate the effect of EZH2/RAI2 on the malignant progression of LUAD cells. The expression levels of EZH2, RAI2 and p53 were examined by Western blot.

RESULTS

Upregulation of EZH2 was identified in LUAD tissues and cells. RAI2 was a downstream target gene of EZH2, and the two were negatively correlated. Silencing EZH2 suppressed proliferation of LUAD cells, promoted expression of p53, cell cycle arrest and apoptosis. While silencing RAI2 could reverse the above-mentioned effects caused by EZH2 silencing.

CONCLUSION

These results demonstrated that EZH2 promoted malignant progression and DNA damage repair of LUAD cells by targeting and negatively regulating RAI2.