Bcl-2 Modulation in p53 Signaling Pathway by Flavonoids: A Potential Strategy towards the Treatment of Cancer

Molecular-Scale Investigations Reveal the Effect of Natural Polyphenols on BAX/Bcl-2 Interactions

Apoptosis signaling controls the cell cycle through the protein-protein interactions (PPIs) of its major B-cell lymphoma 2-associated x protein (BAX) and B-cell lymphoma 2 protein (Bcl-2). Due to the antagonistic function of both proteins, apoptosis depends on a properly tuned balance of the kinetics of BAX and Bcl-2 activities. The utilization of natural polyphenols to regulate the binding process of PPIs is feasible. However, the mechanism of this modulation has not been studied in detail. Here, we utilized atomic force microscopy (AFM) to evaluate the effects of polyphenols (kaempferol, quercetin, dihydromyricetin, baicalin, curcumin, rutin, epigallocatechin gallate, and gossypol) on the BAX/Bcl-2 binding mechanism. We demonstrated at the molecular scale that polyphenols quantitatively affect the interaction forces, kinetics, thermodynamics, and structural properties of BAX/Bcl-2 complex formation. We observed that rutin, epigallocatechin gallate, and baicalin reduced the binding affinity of BAX/Bcl-2 by an order of magnitude. Combined with surface free energy and molecular docking, the results revealed that polyphenols are driven by multiple forces that affect the orientation freedom of PPIs, with hydrogen bonding, hydrophobic interactions, and van der Waals forces being the major contributors. Overall, our work provides valuable insights into how molecules tune PPIs to modulate their function.

Modulatory Properties of Aloe secundiflora's Methanolic Extracts on Targeted Genes in Colorectal Cancer Management

Colon tumors have a very complicated and poorly understood pathogenesis. Plant-based organic compounds might provide a novel source for cancer treatment with a sufficient novel mode of action. The objective of this study was to analyze and evaluate the efficacy of Aloe secundiflora's (AS) methanolic extracts on the expression of CASPS9, 5-LOX, Bcl2, Bcl-xL, and COX-2 in colorectal cancer (CRC) management. Caco-2 cell lines were used in the experimental study. In the serial exhaustive extraction (SEE) method, methanol was utilized as the extraction solvent. Upon treatment of CASPS9 with the methanolic extracts, the expression of the genes was progressively upregulated, thus, dose-dependently increasing the rate of apoptosis. On the other hand, the expressions of 5-LOX, Bcl2, and Bcl-xL were variably downregulated in a dose-dependent manner. This is a unique novel study that evaluated the effects of AS methanolic extracts in vitro on CRC cell lines using different dosage concentrations. We, therefore, recommend the utilization of AS and the application of methanol as the extraction solvent of choice for maximum modulatory benefits in CRC management. In addition, we suggest research on the specific metabolites in AS involved in the modulatory pathways that suppress the development of CRC and potential metastases.

Regulatory activities of Warbugia ugandensis ethanolic extracts on colorectal cancer-specific genome expression dose-dependently

The evaluation of natural biomass sources is a promising strategy in accelerating the development of novel anti-cancer medications. Our study aimed to evaluate the activity of W. ugandensis ethanolic roots and stems extracts on the expression of five targeted genes (COX-2, CASPS-9, Bcl-xL, Bcl2 and 5-LOX) in colorectal cancer (CRC) cell lines (Caco-2). Plant extracts were obtained using serial exhaustive extraction and dissolved in Dimethyl sulfoxide appropriately for bioassay. Caco-2 cell lines were passaged, treated with plant extracts at varying concentrations and their RNA's isolated for evaluation. Our unique study reports on W. ugandensis as efficient natural inhibitors of CRC growth, by directly linking its phytoconstituents to; downregulation of COX-2, 5-LOX, Bcl-xL, Bcl2 and upregulation of CASPS9 genes dose-dependently. We present W. ugandensis ethanolic roots and stems extracts as promising natural inhibitors for CRC carcinogenesis and recommend in vivo and subsequent clinical trials, with substantial clinical effects postulated. We further suggest studies on identification and characterization of the specific metabolites in W. ugandensis involved in the modulatory mechanisms, resulting to inhibition of CRC growth and possible metastases.

Anticancer Potential of Flavonoids: An Overview with an Emphasis on Tangeretin

Natural compounds with pharmacological activity, flavonoids have been the subject of an exponential increase in studies in the field of scientific research focused on therapeutic purposes due to their bioactive properties, such as antioxidant, anti-inflammatory, anti-aging, antibacterial, antiviral, neuroprotective, radioprotective, and antitumor activities. The biological potential of flavonoids, added to their bioavailability, cost-effectiveness, and minimal side effects, direct them as promising cytotoxic anticancer compounds in the optimization of therapies and the search for new drugs in the treatment of cancer, since some extensively antineoplastic therapeutic approaches have become less effective due to tumor resistance to drugs commonly used in chemotherapy. In this review, we emphasize the antitumor properties of tangeretin, a flavonoid found in citrus fruits that has shown activity against some hallmarks of cancer in several types of cancerous cell lines, such as antiproliferative, apoptotic, anti-inflammatory, anti-metastatic, anti-angiogenic, antioxidant, regulatory expression of tumor-suppressor genes, and epigenetic modulation.

Kaempferol and Fisetin-Related Signaling Pathways Induce Apoptosis in Head and Neck Cancer Cells

Despite the relative effectiveness of standard cancer treatment strategies, head and neck cancer (HNC) is still considered one of the leading causes of mortality and morbidity. While selected bioactive compounds of plant origin reveal a pro-apoptotic effect, kaempferol and fisetin flavonols have been reported as potential anti-cancer agents against malignant neoplasms. To date, their exact role in signaling pathways of head and neck cancer cells is largely unknown. Based on the various methods of cytotoxicity testing, we elucidated that kaempferol and fisetin inhibit proliferation, reduce the capacity of cell migration, and induce apoptosis in SCC-9, SCC-25, and A-253 HNC cells in a dose-dependent manner in vitro (p < 0.05, fisetin IC₅₀ values of 38.85 µM, 62.34 µM, and 49.21 µM, and 45.03 µM, 49.90 µM, and 47.49 µM for kaempferol-SCC-9, SCC-25, and A-253, respectively). The obtained results showed that exposure to kaempferol and fisetin reduces Bcl-2 protein expression, simultaneously leading to the arrest in the G2/M and S phases of the cell cycle. Kaempferol and fisetin inhibit cell proliferation by interfering with the cell cycle, which is strongly associated with the induction of G2/M arrest, and induce apoptosis by activating caspase-3 and releasing cytochrome c in human HNC cells. In addition, investigating flavonols, by inhibiting anti-apoptotic proteins from the Bcl-2 family and damaging the mitochondrial transmembrane potential, increased the level of cytochrome c. While flavonols selectively induce apoptosis of head and neck cancer cells, they may support oncological therapy as promising agents. The discovery of new derivatives may be a breakthrough in the search for effective chemotherapeutic agents with less toxicity and thus fewer side effects.

Advances in Bcl-xL Research 2.0

Apoptosis is a form of programmed cell death that is highly conserved in metazoan organisms, where it ensures the proper development and homeostasis of tissues [...].

Systems Pharmacology-Based Strategy to Investigate the Mechanism of Ruangan Lidan Decoction for Treatment of Hepatocellular Carcinoma

epatocellular carcinoma (HCC) is one of the leading contributors to cancer mortality worldwide. Currently, the prevention and treatment of HCC remains a major challenge. As a traditional Chinese medicine (TCM) formula, Ruangan Lidan decoction (RGLD) has been proved to own the effect of relieving HCC symptoms. However, due to its biological effects and complex compositions, its underlying mechanism of actions (MOAs) have not been fully clarified yet. In this study, we proposed a pharmacological framework to systematically explore the MOAs of RGLD against HCC. We firstly integrated the active ingredients and potential targets of RGLD. We next highlighted 25 key targets that played vital roles in both RGLD and HCC disease via a protein-protein interaction (PPI) network and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Furthermore, an ingredient-target network of RGLD consisting of 216 ingredients with 306 targets was constructed, and multilevel systems pharmacology analyses indicated that RGLD could act on multiple biological processes related to the pathogenesis of HCC, such as cellular response to hypoxia and cell proliferation. Additionally, integrated pathway analysis of RGLD uncovered that RGLD might treat HCC through regulating various pathways, including MAPK signaling pathway, PI3K/Akt signaling pathway, TNF signaling pathway, and ERBB signaling pathway. Survival analysis results showed that HCC patients with low expression of VEGFA, HIF1A, CASP8, and TOP2A were related with a higher survival rate than those with high expression, indicating the potential clinical significance for HCC. Finally, molecular docking results of core ingredients and targets further proved the feasibility of RGLD in the treatment of HCC. Overall, this study indicates that RGLD may treat HCC through multiple mechanisms, which also provides a potential paradigm to investigate the MOAs of TCM prescription.

Dietary flavonoid carvacrol triggers the apoptosis of human breast cancer MCF-7 cells via the p53/Bax/Bcl-2 axis

Recently, numerous studies have shown that natural compounds such as carvacrol can be used as therapeutic agents for medicinal purposes. Although carvacrol was found to suppress breast cancer cell lines, however, whether the therapeutic effect of carvacrol on breast cancer is caused by increasing the expression of pro-apoptotic genes in the MCF-7 cell line has not been studied. In this research, we investigate the effect of carvacrol on the expression of P53, pro-apoptotic Bax and anti-apoptotic BCL-2 genes in MCF-7 cells. After preparation and cultivation of MCF-7 cells, the IC50 value of carvacrol on the cells was evaluated by MTT assay, and then apoptosis induction was observed in the cell line treated with different concentrations of carvacrol by DAPI staining. To assess the expression level of Bax, P53 and Bcl-2 both in genes and protein levels QPCR method and western blot analysis were used. According to the results of the research, it was determined that the IC50 of carvacrol compound in MCF-7 cells is 305 µM. DAPI staining exhibit apoptosis and morphological changes in treated MCF-7 cells. Real-time PCR assay and western blot showed increasing the Bax and P53 expression and decreasing the expression of the Bcl-2 anti-apoptotic gene and protein. These results showed that carvacrol has cell growth inhibition effects on the MCF-7 cancer cell line. Carvacrol-induced p53-dependent apoptosis, which might be related to the Bax/Bcl-2 associated pathway. These results indicated that carvacrol could be considered suitable for the prevention and treatment of breast cancer.

Identification of epigenetic dysregulation gene markers and immune landscape in kidney renal clear cell carcinoma by comprehensive genomic analysis

Kidney cancer is one the most lethal cancers of the urinary system, but current treatments are limited and its prognosis is poor. This study focused on kidney renal clear cell carcinoma (KIRC) and analyzed the relationship between epigenetic alterations and KIRC prognosis, and explored the prognostic significance of these findings in KIRC patients. Based on multi-omics data, differentially expressed histone-modified genes were identified using the R package limma package. Gene enhancers were detected from data in the FANTOM5 database. Gene promoters were screened using the R package ChIPseeker, and the Bumphunter in the R package CHAMP was applied to screen differentially methylated regions (DMR). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene Ontology (GO) functional enrichment analysis of genes was performed using the R package clusterProfiler. We identified 51 dysregulated epigenetic protein coding genes (epi-PCGs) from 872 epi-PCGs, and categorized three molecular subtypes (C1, C2, and C3) of KIRC samples with significantly different prognosis. Notably, among the three molecular subtypes, we found a markedly differential immune features in immune checkpoints, cytokines, immune signatures, and immune cell distribution. C2 subtype had significantly lower enrichment score of IFNγ, cytotoxic score (CYT), and angiogenesis. In addition, an 8-gene signature containing 8 epi-PCGs (ETV4, SH2B3, FATE1, GRK5, MALL, HRH2, SEMA3G, and SLC10A6) was developed for predicting KIRC prognosis. Prognosis of patients with a high 8-gene signature score was significantly worse than those with a low 8-gene signature score, which was also validated by the independent validation data. The 8-gene signature had a better performance compared with previous signatures of KIRC. Overall, this study highlighted the important role of epigenetic regulation in KIRC development, and explored prognostic epi-PCGs, which may provide a guidance for exploiting further pathological mechanisms of KIRC and for developing novel drug targets.

Modulation of TLR/NF-κB/NLRP Signaling by Bioactive Phytocompounds: A Promising Strategy to Augment Cancer Chemotherapy and Immunotherapy

Background

Tumors often progress to a more aggressive phenotype to resist drugs. Multiple dysregulated pathways are behind this tumor behavior which is known as cancer chemoresistance. Thus, there is an emerging need to discover pivotal signaling pathways involved in the resistance to chemotherapeutic agents and cancer immunotherapy. Reports indicate the critical role of the toll-like receptor (TLR)/nuclear factor-κB (NF-κB)/Nod-like receptor pyrin domain-containing (NLRP) pathway in cancer initiation, progression, and development. Therefore, targeting TLR/NF-κB/NLRP signaling is a promising strategy to augment cancer chemotherapy and immunotherapy and to combat chemoresistance. Considering the potential of phytochemicals in the regulation of multiple dysregulated pathways during cancer initiation, promotion, and progression, such compounds could be suitable candidates against cancer chemoresistance.

Objectives

This is the first comprehensive and systematic review regarding the role of phytochemicals in the mitigation of chemoresistance by regulating the TLR/NF-κB/NLRP signaling pathway in chemotherapy and immunotherapy.

Methods

A comprehensive and systematic review was designed based on Web of Science, PubMed, Scopus, and Cochrane electronic databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to include papers on TLR/NF-κB/NLRP and chemotherapy/immunotherapy/chemoresistance by phytochemicals.

Results

Phytochemicals are promising multi-targeting candidates against the TLR/NF-κB/NLRP signaling pathway and interconnected mediators. Employing phenolic compounds, alkaloids, terpenoids, and sulfur compounds could be a promising strategy for managing cancer chemoresistance through the modulation of the TLR/NF-κB/NLRP signaling pathway. Novel delivery systems of phytochemicals in cancer chemotherapy/immunotherapy are also highlighted.

Conclusion

Targeting TLR/NF-κB/NLRP signaling with bioactive phytocompounds reverses chemoresistance and improves the outcome for chemotherapy and immunotherapy in both preclinical and clinical stages.

Aberrant Expression of miR-1301 in Human Cancer

miR-1301 is a newly discovered miRNA, which is abnormally expressed in 14 types of tumors. miR-1301 inhibits 23 target genes, forms a ceRNA network with 2 circRNAs and 8 lncRNAs, and participates in 6 signaling pathways, thereby affecting tumor cell proliferation, invasion, metastasis, apoptosis, angiogenesis, etc. Abnormal expression of miR-1301 is often associated with poor prognosis of cancer patients. In addition, miR-1301 is related to the anti-tumor effect of epirubicin on osteosarcoma and imatinib on chronic myeloid leukemia(CML) and can enhance the cisplatin sensitivity of ovarian cancer. This work systematically summarizes the abnormal expression and prognostic value of miR-1301 in a variety of cancers, depicts the miR-1301-related signaling pathways and ceRNA network, and provides potential clues for future miR-1301 research.

MY11 exerts antitumor effects through activation of the NF-κB/PUMA signaling pathway in breast cancer

Breast cancer is the most common malignancy in women worldwide, and the discovery of new effective breast cancer therapies with lower toxicity is still needed. We screened a series of chalcone derivatives and found that MY11 ((E)-1-(2-hydroxy-4,6-dimethoxyphenyl)-3-(4-piperazinylphenyl) prop-2-en-1-one) had the strongest anti-breast cancer activity. MY11 inhibited the growth of MDA-MB-231 and MCF-7 breast cancer cells by arresting the cell cycle and promoting apoptosis, through regulation of the cell cycle and apoptosis-related proteins. PDTC (Pyrrolidinedithiocarbamate ammonium), a specific inhibitor of the NF-κB pathway, abolished the inhibitory effect of MY11 treatment. NF-κB has been shown to regulate PUMA-dependent apoptosis. Our in vitro studies demonstrated that MY11 promoted breast cancer cell apoptosis by activating the NF-κB/PUMA/mitochondrial apoptosis pathway (including Bcl-2, Bax, and Caspase-9). MY11 also inhibited tumor growth in an orthotopic breast cancer mouse model by inducing apoptosis through the NF-κB signaling pathway, importantly, with minimal toxicity. In addition, MY11 was found by docking analysis to bind to p65, which might enhance the stability of the p65 protein. Taken together, our findings indicate that MY11 exerts a significant anticancer effect in breast cancer and that it may be a potential candidate for the treatment of breast cancer.