Targeting regulated cell death with plant natural compounds for cancer therapy: A revisited review of apoptosis, autophagy-dependent cell death, and necroptosis

Isoxazole based nucleosides induce autophagy through the production of ROS and the suppression of the β-catenin pathway in human colorectal carcinoma cells

β-catenin is frequently implicated in signaling pathways that regulate autophagy, and the production of reactive oxygen species (ROS) has been linked to autophagy activation. Isoxazole-based nucleoside compounds have demonstrated anti-cancer properties. In this study, we report the identification of novel isoxazole-nucleosides as anti-tumor agents and their impact on autophagy in human colorectal carcinoma (CRC) cells. Among the ITP series, ITP-7 and ITP-9 (ITP-7/9) exhibited significant cytotoxicity compared to other compounds. Treatment with ITP-7/9 upregulated the expression of key autophagy-related proteins, including LC3 II, Atg7, and phosphorylated Beclin-1. Additionally, ITP-7/9 promoted the formation of LC3 II puncta and increased the number of AO-stained and MDC-stained cells, indicating enhanced autophagy. ROS levels were elevated following ITP-7/9 exposure, and treatment with N-acetyl l-cysteine (NAC), a ROS inhibitor, reduced the ITP-7/9-induced expression of LC3 II. Furthermore, ITP-7/9 inhibited β-catenin's role as a transcription factor, as observed in ICC assays. Moreover, cells with β-catenin gene deletion exhibited stronger autophagy when treated with ITP-7/9 compared to those treated with ITP-7/9 alone. These findings suggest that ITP-7/9 induces autophagy and promotes CRC cell death by downregulating β-catenin.

Atramacronoid A induces the PANoptosis-like cell death of human breast cancer cells through the CASP-3/PARP-GSDMD-MLKL pathways

Breast cancer is the most common malignant tumor and a major cause of mortality among women worldwide. Atramacronoid A (AM-A) is a unique natural sesquiterpene lactone isolated from the rhizome of Atractylodes macrocephala Koidz (known as Baizhu in Chinese). Our study demonstrated that AM-A triggers a specific form of cell death resembling PANoptosis-like cell death. Further analysis indicated that AM-A-induced PANoptosis-like cell death is associated with the CASP-3/PARP-GSDMD-MLKL pathways, which are mediated by mitochondrial dysfunction. These results suggest the potential of AM-A as a lead compound and offer insights for the development of therapeutic agents for breast cancer from natural products.

Punicalagin Restricts Growth, Promotes Apoptosis, and Reduces Invasion in Human Gastric Cancer Cells

This research investigated the anticancer properties of punicalagin, a prominent bioactive polyphenol extracted from Punica granatum L, in human gastric cancer cell lines. Normal and gastric cancer cells were exposed to different doses of punicalagin for various durations. Punicalagin exhibited cytotoxic effects on gastric cancer cells in a dose- and time-dependent fashion, while sparing normal gastric epithelial cells. It is noteworthy that among the 3 gastric cancer cells, HGC-27 cells were more resistant to punicalagin than 23,132/87 and AGS cells. Furthermore, punicalagin triggered apoptosis in gastric cancer cells, evidenced by a rise in both early and late apoptotic cell percentages. Western blot analysis further revealed that punicalagin elevated the levels of activated caspase-3. Conversely, punicalagin curtailed cell invasion and reduced the expression of MMP-2, MMP-9, Snail, and Slug. From a mechanistic standpoint, Western blotting indicated that punicalagin might inhibit the Erk and NF-κB pathways, leading to apoptosis induction and the inhibition of cell invasion in gastric cancer cells. These results indicate that punicalagin promotes apoptosis and inhibits cell invasion in gastric cancer cells by activating caspase-3 and suppressing MMP-2, MMP-9, Snail, and Slug through the inhibition of the Erk and NF-κB pathways.

Dysregulated CREB3 cleavage at the nuclear membrane induces karyoptosis-mediated cell death

Cancer cells often exhibit resistance to apoptotic cell death, but they may be vulnerable to other types of cell death. Elucidating additional mechanisms that govern cancer cell death is crucial for developing new therapies. Our research identified cyclic AMP-responsive element-binding protein 3 (CREB3) as a crucial regulator and initiator of a unique cell death mechanism known as karyoptosis. This process is characterized by nuclear shrinkage, deformation, and the loss of nuclear components following nuclear membrane rupture. We found that the N-terminal domain (aa 1-230) of full-length CREB3 (CREB3-FL), which is anchored to the nuclear inner membrane (INM), interacts with lamins and chromatin DNA. This interaction maintains a balance between the outward force exerted by tightly packed DNA and the inward constraining force, thereby preserving INM integrity. Under endoplasmic reticulum (ER) stress, aberrant cleavage of CREB3-FL at the INM leads to abnormal accumulation of the cleaved form of CREB3 (CREB3-CF). This accumulation disrupts the attachment of CREB3-FL to the INM, resulting in sudden rupture of the nuclear membrane and the onset of karyoptosis. Proteomic studies revealed that CREB3-CF overexpression induces a DNA damage response akin to that caused by UVB irradiation, which is associated with cellular senescence in cancer cells. These findings demonstrated that the dysregulation of CREB3-FL cleavage is a key factor in karyoptotic cell death. Consequently, these findings suggest new therapeutic strategies in cancer treatment that exploit the process of karyoptosis.

Design, synthesis, and pharmacological evaluation of novel benzothiazole derivatives targeting LCK in acute lymphoblastic leukemia

Lymphocyte-specific protein tyrosine kinase (LCK), a member of the Src family of tyrosine kinases, is implicated in the pathogenesis of almost all types of leukemia via T cells activation and signal transduction. LCK is highly expressed in acute lymphoblastic leukemia (ALL), and knockdown of the LCK gene can significantly inhibit the proliferation of leukemia cell lines. Here, we designed and synthesized a series of benzothiazole derivatives as novel LCK inhibitors using both docking-based virtual screening and activity assays for structural optimization. Among these compounds, 7 m showed a strong inhibitory activity in the proliferation of leukemia cell lines and LCK kinase activity. Moreover, we found that compound 7 m could induce apoptosis while simultaneously blocking cell cycle via decreasing its phosphorylation at Tyr394 of the LCK. Collectively, these findings shed new light on compound 7 m that would be utilized as a promising drug candidate with apoptosis-triggered and cell cycle arrest activities for the future ALL therapy.

Disulfidptosis-related signatures for prognostic and immunotherapy reactivity evaluation in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world and a nonnegligible health concern on a worldwide scale. Disulfidptosis is a novel mode of cell death, which is mainly caused by the collapse of the actin skeleton. Although many studies have demonstrated that various types of cell death are associated with cancer treatment, the relationship between disulfidptosis and HCC has not been elucidated.

METHODS

Here, we mainly applied bioinformatics methods to construct a disulfidptosis related risk model in HCC patients. Specifically, transcriptome data and clinical information were downloaded from the Gene Expression Omnibus (GEO), International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA) database. A total of 45 co-expressed genes were extracted between the disulfidptosis-related genes (DRGs) and the differential expression genes (DEGs) of liver hepatocellular carcinoma (LIHC) in the TCGA database. The LIHC cohort was divided into two subgroups with different prognosis by k-mean consensus clustering and functional enrichment analysis was performed. Subsequently, three hub genes (CDCA8, SPP2 and RDH16) were screened by Cox regression and LASSO regression analysis. In addition, a risk signature was constructed and the HCC cohort was divided into high risk score and low risk score subgroups to compare the prognosis, clinical features and immune landscape between the two subgroups. Finally, the prognostic model of independent risk factors was constructed and verified.

CONCLUSIONS

High DRGs-related risk score in HCC individuals predict poor prognosis and are associated with poor immunotherapy response, which indicates that risk score assessment model can be utilized to guide clinical treatment strategy.

A prognostic risk model for programmed cell death and revealing TRIB3 as a promising apoptosis suppressor in renal cell carcinoma

Programmed cell death (PCD), a common modality of cell death, affects tumor development and acts as a target for tumor therapeutics. Many modalities of PCD regulate genesis, progression and metastasis of cancers, thus affecting the patients' prognosis, but the comprehensive molecular mechanisms of PCD in tumors are lacking, especially in renal cancer. Here, seventeen PRPCDGs were identified from 1257 genes associated with thirteen PCD modalities, which were highly differentially expressed and significantly affected patients' prognosis. Then, LASSO regression analysis of these PRPCDGs screened the 9-gene PRPCDGs risk signature in TCGA-KIRC database. The PRPCDGs risk signature was closely associated with the patients' prognosis and presented stable prediction efficacy for 5- and 7-year overall survival (OS) in three different cohorts of renal cancer. Immune cell infiltration, immune checkpoint expression and pathway enrichment (including GO, KEGG pathway, tumor-associated pathways and metabolism-associated pathways) were significantly different in the high- or low-PRPCDGs-risk group. Finally, we illustrated that TRIB3 might be a protumor factor responsible for the elevated proliferation and invasion capacities of renal cell carcinoma (RCC) cells. In summary, the PRPCDGs risk signature was developed and showed stable prediction efficacy for the prognosis of patients and that (such as TRIB3) could be a potential target for RCC management.

In vitro antioxidant and anticancer activities of Smilax corbularia extract combined with Phellinus linteus extract against breast cancer cell lines

Treatment with extracts from whole herbs has been reported to synergistically enhance the anticancer activities of therapeutic agents in recent studies. The present study evaluated the antioxidant and anticancer activities of Smilax corbularia Kunth (S. corbularia) and Phellinus linteus (P. linteus) crude extracts individually and in combination. S. corbularia was extracted using ethanol, whereas P. linteus was extracted using hot water. Both crude extracts underwent physiochemical characterization. Subsequently, the possible antioxidant activities of both crude extracts, individually and in combination, were evaluated using 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assays. Their effects on breast cancer cell cytotoxicity, proliferation and apoptosis were then assessed. The crude S. corbularia extract obtained was found to have a high level of total phenolic content, whilst the crude P. linteus extract had high levels of total polysaccharide content. The total phenolic content and total polysaccharide content results of the combinations depended on the respective ratios of the individual extracts. S. corbularia alone and combination 3 (which contained 75% S. corbularia: 25% P. linteus) demonstrated the greatest radical scavenging activity, followed by combination 1 (50% S. corbularia: 50% P. linteus), combination 2 (25% S. corbularia: 75% P. linteus) and P. linteus. The toxicity results of the extract samples on the cancer cells corresponded with their antioxidant activity. In particular, certain combinations demonstrated clearer inhibitory effects on cell proliferation against three types of breast cancer cells compared with those exerted by the two individual extracts. However, induction of apoptosis was limited, with the degree of apoptosis observed to be #x003C;5%. These findings suggested that treatment with combinations of these two extracts could confer enhanced antioxidant and antiproliferative effects on breast cancer cells. Therefore, the potential of these two extracts in combination as anticancer agents warrants further investigation.