[Protein CD133 as a tumor stem cell marker]

PAX2 induces endometrial cancer by inhibiting mitochondrial function via the CD133-AKT1 pathway

Endometrial cancer (EC) is a malignancy of the endometrial epithelium. The prevalence and mortality rates associated with the disease are on the rise globally. A total of 20 cases of type I EC tissues were collected for transcriptomic sequencing, our findings indicate that PAX2 is highly expressed in EC tissues and is closely related to the pathogenesis of EC. PAX2 is a member of the paired homeobox domain family and has been linked to the development of a number of different tumours. In normal endometrial tissue, PAX2 is methylated; however, in EC, it is demethylated. Nevertheless, few studies have focused on its role in EC. A protein-protein interaction (PPI) analysis revealed a regulatory relationship between PAX2 and CD133, which in turn affects the activity of AKT1. CD133 is a well-known marker of tumor stem cells and is involved in tumor initiation, metastasis, recurrence, and drug resistance; AKT1 promotes cell survival by inhibiting apoptosis and is considered a major promoter of many types of cancer. Nevertheless, further investigation is required to ascertain whether PAX2 affects the progression of EC by regulating the CD133-AKT1 pathway. The present study demonstrated that PAX2 promoted cell proliferation, migration, invasion and adhesion, and inhibited apoptosis. Its mechanism of action was found to be the inhibition of mitochondrial oxidative phosphorylation, promotion of glycolysis, increase in mitochondrial copy number, and increase in the levels of reactive oxygen species (ROS) and hexokinase, as well as the concentration of mitochondrial calcium ions. This was achieved through the promotion of CD133 expression and the phosphorylation of AKT1. In conjunction with the aforementioned regulatory pathways, the progression of EC is facilitated.

CD133 ligand-enhanced etoposide-liposome complex for targeted killing of lung cancer cells

Lung cancer has a high incidence rate and a low cure rate, hence the urgent need for effective treatment methods. Current lung cancer drugs have several drawbacks, including low specificity, poor targeting, drug resistance, and irreversible damage to normal tissues. Therefore, there is a need to develop a safe and effective new drug that can target and kill tumor cells. In this study, we combined nanotechnology and biotechnology to develop a CD133 ligand-modified etoposide-liposome complex (Lipo@ETP-CD133) for targeted therapy of lung cancer. The CD133 ligand targeted lung cancer stem cells, causing the composite material to aggregate at the tumor site, where high levels of ETP liposomes could exert a strong tumor-killing effect. Our research results demonstrated that this nano-drug had efficient targeting and tumor-killing effects, indicating its potential for clinical application.

Proanthocyanidins inhibited colorectal cancer stem cell characteristics through Wnt/β-catenin signaling

BACKGROUND

Cancer stem cells (CSCs) play a key role in tumor cell growth, drug resistance, recurrence, and metastasis. Proanthocyanidins (PC) is widely existed in plants and endowed with powerful antioxidant and anti-aging effects. Interestingly, recent studies have found that PC exhibits the inhibitory effect on tumor growth. However, the role of PC in CSCs of colorectal cancer (CRC) and molecular mechanism remain unclear.

METHODS

CCK-8, colony, and tumorsphere formation assay were used to evaluate cancer cell viability and stemness, respectively. Western blotting was used to detect the protein expression. Tumor xenograft experiments were employed to examine the tumorigenicity of CRC cells in nude mice.

RESULTS

PC decreased the proliferation of CRC cells (HT29 and HCT-116), and improved the sensitivity of CRC cells to oxaliplatin (L-OHP), as well as inhibited tumor growth in nude mice. Further studies showed that PC also down-regulated CSCs surface molecular and stemness transcriptional factors, while suppressed the formations of tumorspheres and cell colony in CRC. In addition, PC-impaired proteins expressions of p-GSK3β, β-catenin and DVL1-3. LiCl, an activator of the Wnt/β-catenin signaling, rescued PC-induced downregulation of CSCs markers, and reduction of tumorspheres and cell colony formation abilities in CRC cells. Furthermore, the effects of PC on inhibiting cell proliferation and enhancing L-OHP sensitivity were impaired by LiCl.

CONCLUSIONS

PC exerted an inhibitory effect on CSCs via Wnt/β-catenin in CRC, and may be a potential new class of natural drug for CRC treatment.