Independent and opposing associations of dietary phytosterols intake and PLCE1 rs2274223 polymorphisms on esophageal squamous cell carcinoma risk

β-Sitosterol Inhibits Tumor Growth and Amplifies Rituximab Sensitivity through Acid Sphingomyelinase/Ceramide Signaling in Diffuse Large B-Cell Lymphoma

Rituximab (RTX) resistance is a notable challenge in treating diffuse large B-cell lymphoma (DLBCL). β-Sitosterol (β-ST) is a plant sterol that has been found in a broad variety of fruits, spices, and medicinal plants. The antineoplastic properties of β-ST are established in various solid malignancies; however, its effect on DLBCL is uncharted. This study investigates the role of β-ST in DLBCL as well as the underlying mechanisms. Our findings indicated that β-ST impeded DLBCL cell proliferation in a concentration- and time-dependent manner. β-ST appeared to alter sphingolipid metabolism, facilitate acid sphingomyelinase (ASM) translocation to the plasma membrane, augment ceramide platforms through increased ceramide synthesis, and consequently induce apoptosis in DLBCL cells. Furthermore, we found that RTX initiated both apoptotic and survival pathways in vitro, with the former contingent on the transient activation of the ASM, and β-ST could amplify the anti-DLBCL efficacy of RTX by modulating ASM/Ceramide (Cer) signaling. Collectively, our findings elucidate the mechanistic role of β-ST in DLBCL and underscore its potential in amplifying the antineoplastic efficacy of RTX via ASM activation, proposing a potential avenue to improve the efficacy of RTX therapy.

Phytosterols: Physiological Functions and Potential Application

Dietary intake of natural substances to regulate physiological functions is currently regarded as a potential way of promoting health. As one of the recommended dietary ingredients, phytosterols that are natural bioactive compounds distributed in plants have received increasing attention for their health effects. Phytosterols have attracted great attention from scientists because of many physiological functions, for example, cholesterol-lowering, anticancer, anti-inflammatory, and immunomodulatory effects. In addition, the physiological functions of phytosterols, the purification, structure analysis, synthesis, and food application of phytosterols have been widely studied. Nowadays, many bioactivities of phytosterols have been assessed in vivo and in vitro. However, the mechanisms of their pharmacological activities are not yet fully understood, and in-depth investigation of the relationship between structure and function is crucial. Therefore, a contemporaneous overview of the extraction, beneficial properties, and the mechanisms, as well as the current states of phytosterol application, in the food field of phytosterols is provided in this review.

Prognostic Risk Models Using Epithelial Cells Identify β-Sitosterol as a Potential Therapeutic Target Against Esophageal Squamous Cell Carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is an aggressive and fatal malignancy that leads to epithelial cancer. The association between epithelial cell heterogeneity, prognosis, and immune response in this cancer remains uncertain. This study aimed to investigate epithelial cell heterogeneity in ESCC and develop a predictive risk model using the identified cell types.

Methods

Single-cell RNA sequencing (scRNA-seq) and differential ESCC gene data were accessed from the Gene Expression Omnibus. Functional enrichment analysis, inferCNV, cell development trajectories, and intercellular communication were analyzed following epithelial cell characterization. Differentially expressed ESCC (n = 773) and epithelial cell marker genes (n = 3407) were intersected to obtain core genes, and epithelial cell-related prognostic genes were identified. LASSO regression analysis was used to construct a prognostic model. The external dataset GSE53624 was used to further validate the stability of the model. Drug sensitivity predictions, and immune cell infiltration were analyzed. Molecular docking clarified the possible therapeutic role of β-sitosterol in ESCC. Finally, wound healing assay, cell colony, and transwell assay were constructed to detect the effects of the core gene PDLIM2 on ESCC cell proliferation, invasion, and migration.

Results

Eight cell clusters were identified, and epithelial cells were categorized into tumor and paratumor groups. The tumor group possessed more chromosomal variants than the paratumor group. Epithelial cells were associated with multiple cell types and significantly correlated with the Wnt, transforming growth factor, and epidermal growth factor signaling pathways. From 231 intersected genes, five core genes were screened for use in the risk model: CTSL, LAPTM4B, MYO10, NCF2, and PDLIM2. These genes may contribute to the cancerous transformation of normal esophageal epithelial cells and thereby act as biomarkers and potential therapeutic targets in patients with ESCC. β-Sitosterol furthermore displayed excellent docking potential with these genes. Meanwhile, further experiments demonstrated that the gene PDLIM2 plays a major role in the progression of oesophageal squamous carcinoma.

Conclusion

We successfully developed a risk model for the prognosis of ESCC based on epithelial cells that addresses the response of ESCC to immunotherapy and offers novel cancer treatment options.

β-Sitosterol targets ASS1 for Nrf2 ubiquitin-dependent degradation, inducing ROS-mediated apoptosis via the PTEN/PI3K/AKT signaling pathway in ovarian cancer

The exploration of drugs derived from natural sources holds significant promise in addressing current limitations in ovarian cancer (OC) treatments. While previous studies have highlighted the remarkable anti-cancer properties of the natural compound β-sitosterol (SIT) across various tumors, its specific role in OC treatment remains unexplored. This study aims to investigate the anti-tumor activity of SIT in OC using in vitro and in vivo models, delineate potential mechanisms, and establish a preclinical theoretical foundation for future clinical trials, thus fostering further research. Utilizing network pharmacology, we pinpoint SIT as a promising candidate for OC treatment and predict its potential targets and pathways. Through a series of in vitro and in vivo experiments, we unveil a novel mechanism through which SIT mitigates the malignant biological behaviors of OC cells by modulating redox status. Specifically, SIT selectively targets argininosuccinate synthetase 1 (ASS1), a protein markedly overexpressed in OC tissues and cells. Inhibiting ASS1, SIT enhances the interaction between Nrf2 and Keap1, instigating the ubiquitin-dependent degradation of Nrf2, subsequently diminishing the transcriptional activation of downstream antioxidant genes HO-1 and NQO1. The interruption of the antioxidant program by SIT results in the substantial accumulation of reactive oxygen species (ROS) in OC cells. This, in turn, upregulates PTEN, exerting negative regulation on the phosphorylation activation of AKT. The suppression of AKT signaling disrupted downstream pathways associated with cell cycle, cell survival, apoptosis, migration, and invasion, ultimately culminating in the death of OC cells. Our research uncovers new targets and mechanisms of SIT against OC, contributing to the existing knowledge on the anti-tumor effects of natural products in the context of OC. Additionally, this research unveils a novel role of ASS1 in regulating the Nrf2-mediated antioxidant program and governing redox homeostasis in OC, providing a deeper understanding of this complex disease.

The role of dietary carotenoids in preventing the development of esophageal squamous cell carcinoma

Background and aims: Experimental studies showed that carotenoids had anti-carcinogenic properties, but epidemiological studies on the association between dietary carotenoids and esophageal squamous cell carcinoma (ESCC) risk were limited, and the findings were inconsistent. This study aimed to investigate the roles of intake of dietary carotenoids in the development of ESCC among a rural Chinese population. Methods: A population-based case-control study was conducted in Southwest China. A total of 915 incident ESCC cases and 925 community-based controls were included. A validated food frequency questionnaire with 76-item was adopted to collect information about dietary consumption. Intake of dietary calories and each carotenoid was calculated according to the China food composition tables. Odds ratios (OR) with 95% confidence intervals (CI) were calculated by a logistic regression model, with adjustments for age, gender, body mass index, family cancer history, cigarette smoking, alcohol drinking, education, marital status, prudent pattern score, and total calories. Results: In comparison to the highest with lowest intake quartiles, intake of total carotenes (OR: 0.70, 95% CI: 0.52-0.96, Ptrend: 0.024), α-carotene (OR: 0.62, 95% CI: 0.46-0.83, Ptrend: 0.014), β-carotene (OR: 0.63, 95% CI: 0.46-0.86, P-trend: 0.005), and the sum of lutein and zeaxanthin (OR: 0.41, 95% CI: 0.29-0.56, Ptrend<0.001) was significantly associated with a decreased risk of ESCC after adjustment for confounders. Conclusions: The results indicated that a higher intake of total carotene, α-carotene, β-carotene, and the sum of lutein and zeaxanthin was associated with a lower risk of ESCC.

β-Sitosterol as a Promising Anticancer Agent for Chemoprevention and Chemotherapy: Mechanisms of Action and Future Prospects

Cancer is one of the primary causes of death worldwide, and its incidence continues to increase yearly. Despite significant advances in research, the search for effective and nontoxic preventive and therapeutic agents remains greatly important. Cancer is a multimodal disease, where various mechanisms play significant roles in its occurrence and progression. This highlights the need for multitargeted approaches that are not only safe and inexpensive but also provide effective alternatives for current therapeutic regimens. β-Sitosterol (SIT), the most abundant phytosterol found in various plant foods, represents such an option. Preclinical evidence over the past few decades has overwhelmingly shown that SIT exhibits multiple anticancer activities against varied cancers, such as liver, cervical, colon, stomach, breast, lung, pancreatic, and prostate cancers, in addition to leukemia, multiple myeloma, melanoma, and fibrosarcoma. In this article, we present the latest advances and perspectives on SIT-systematically summarizing its antitumor mechanisms of action into 7 main sections and combining current challenges and prospects-for its use as a promising agent for cancer prevention and treatment. In particular, SIT plays a role in cancer prevention and treatment mainly by enhancing apoptosis, inducing cell cycle arrest, bidirectionally regulating oxidative stress, improving metabolic reprogramming, inhibiting invasion and metastasis, modulating immunity and inflammation, and combating drug resistance. Although SIT holds such great promise, the poor aqueous solubility and bioavailability coupled with low targeting efficacy limit its therapeutic efficacy and clinical application. Further research on novel drug delivery systems may improve these deficiencies. Overall, through complex and pleiotropic mechanisms, SIT has good potential for tumor chemoprevention and chemotherapy. However, no clinical trials have yet proven this potential. This review provides theoretical basis and rationality for the further design and conduct of clinical trials to confirm the anticancer activity of SIT.

Association of Dietary Phytosterols Intake and Survival of Esophageal Squamous Cell Carcinoma: A Prospective Cohort Study

BACKGROUND

The association of dietary phytosterols intake with survival of esophageal squamous cell carcinoma (ESCC) remains unclear. This study was to examine the effect of dietary phytosterols intake on ESCC survival in a Chinese rural population.

METHODS

A total of 942 incident ESCC patients diagnosed between 2011 and 2013 in Yanting area were followed up until March 1^st, 2020. Dietary intake five years before ESCC diagnosis was collected using a food frequency questionnaire. The outcome of interest was all-cause mortality. Cox proportional hazards regression model was used to estimate hazard ratio (HR) and 95% confidence intervals (CI).

RESULTS

When comparing the highest with lowest intake quartiles, intake of five specific and total phytosterols was not significantly associated with risk of death after adjustment for covariates, the adjusted HR (95% CI) for β-sitosterol, campesterol, stigmasterol, β-sitostanol, campestanol and total phytosterols was 0.90 (95% CI: 0.70-1.16), 0.92 (95% CI: 0.71-1.19), 0.86 (95% CI: 0.66-1.12), 0.93 (95% CI: 0.73-1.20), 0.94 (95% CI: 0.72-1.21), 0.89 (95% CI: 0.69-1.15), respectively.

CONCLUSION

This study does not find any association between pre-diagnostic phytosterols intake and risk of all-cause mortality among ESCC patients. Further research is required to determine the effect of post-diagnostic phytosterols intake on ESCC survival.