Tumour-suppressive effects of curcumin analogs CCA-1.1 and Pentagamavunone-1 in colon cancer: In vivo and in vitro studies

Regulation of cellular senescence in tumor progression and therapeutic targeting: mechanisms and pathways

Cellular senescence, a stable state of cell cycle arrest induced by various stressors or genomic damage, is recognized as a hallmark of cancer. It exerts a context-dependent dual role in cancer initiation and progression, functioning as a tumor suppressor and promoter. The complexity of senescence in cancer arises from its mechanistic diversity, potential reversibility, and heterogeneity. A key mediator of these effects is the senescence-associated secretory phenotype (SASP), a repertoire of bioactive molecules that influence tumor microenvironment (TME) remodeling, modulate cancer cell behavior, and contribute to therapeutic resistance. Given its intricate role in cancer biology, senescence presents both challenges and opportunities for therapeutic intervention. Strategies targeting senescence pathways, including senescence-inducing therapies and senolytic approaches, offer promising avenues for cancer treatment. This review provides a comprehensive analysis of the regulatory mechanisms governing cellular senescence in tumors. We also discuss emerging strategies to modulate senescence, highlighting novel therapeutic opportunities. A deeper understanding of these processes is essential for developing precision therapies and improving clinical outcomes.

Antitumor effect of curcumin analog on osteosarcoma through the inhibition of p300‑mediated histone acetylation

Osteosarcoma (OS) is the most common malignant bone tumor in children and adolescents. Histone acetyltransferases (HATs), such as p300, CBP and PCAF, modulate numerous biological processes, including cellular proliferation and oncogenesis, through histone acetylation. In the present study, it was investigated whether the curcumin analogs such as pentagamavunon‑1 (PGV‑1) and chemoprevention curcumin analog‑1.1 (CCA‑1.1) could target p300 and suppress OS. Computational analysis indicated that PGV‑1 and CCA‑1.1 bind to the HAT domain of p300. Accordingly, these analogs efficiently inhibited the HAT activity of p300 in vitro and promoted OS cell apoptosis, accompanied by downregulation of acetylated histone H3 at Lys‑27 and phosphorylated oncogenic STAT3 at Tyr‑705. Finally, it was found that PGV‑1 and CCA‑1.1 but not PGV‑1, significantly attenuates the growth of OS developed on the chicken egg chorioallantoic membrane (CAM). Collectively, the present results strongly suggest that curcumin analog‑mediated targeting of p300 might provide a clue to develop an effective treatment strategy against patients with OS.

The Combination of Sorafenib and PGV-1 Inhibits the Proliferation of Hepatocellular Carcinoma Through c-Myc Suppression in an Additive Manner: In Vitro Studies

Hepatocellular carcinoma (HCC) is one of the most aggressive types of liver cancer, and it is frequently associated with upregulated c-Myc expression. Sorafenib (Sor) is commonly used to treat HCC, but many patients experienced mild to severe side effects due to prolonged Sor treatment during therapy. It has been known that Pentagamavunone-1 (PGV-1) exhibits a remarkable antiproliferative effect on several cancer cells, yet limited studies have reported its cellular activities in HCC. The current study aims to evaluate the anticancer effects of Sor in combination with PGV-1 on the progression of HCC proliferation. c-Myc expressing cells, JHH-7 and Huh-7, were used for this study, then Sor and PGV-1 were tested for their effect on the cellular physiology phenomena including cytotoxicity combination assay and colony formation assay, cell cycle profile and reactive oxygen species (ROS) level by flow cytometry, senescence induction by beta-galactosidase (SA-β-gal) assay, and migration inhibition by wound healing assay. The c-Myc expression was evaluated through Western blot. PGV-1 was more effective than Sor at inhibiting cell growth, and it showed greater selectivity for HCC over fibroblast cells. The combination of Sor with PGV-1 exhibited synergistic-additive cytotoxicity with an irreversible effect in HCC cell lines. The combination induced senescence similarly with Sor alone in JHH-7 cells, while PGV-1 enhanced the cellular senescence when combined with Sor in Huh-7 cells. Furthermore, the combination increased ROS level in the same way as PGV-1 did in HCC. The combination with PGV-1 acted better than Sor alone to inhibit JHH-7 cell migration. In addition, the combination treatment led to the suppression of c-Myc, particularly in JHH-7 cells. Taken together, combining Sor with PGV-1 promotes better efficacy than Sor alone to inhibit HCC cell proliferation, and further evaluation of the efficacy and safety of adding PGV-1 to Sor in HCC therapy is worthwhile as a potential combination treatment option.

PGV-1 Causes Disarrangement of Spindle Microtubule Organization Resulting in Aberrant Mitosis in HLF and HuH6 Cells Associated with Altered MYCN Status

Purpose

The HLF and HuH-6 cell lines represent hepatocellular carcinoma (HCC) with different characteristics in chromosome content that may give different drug responses. Here, PGV-1 was intended to challenge the growth-suppressing effect on HLF and HuH-6 and trace the molecular target mechanism of action compared to sorafenib.

Methods

We applied MTT cytotoxic assay, colony forming assay, flow cytometry analysis, immunofluorescence assay and western blot assay.

Results

PGV-1 exhibited cytotoxic effects on HLF and HuH-6 with IC-50 values of 1 µM and 2 µM, respectively, whereas sorafenib showed less cytotoxicity with IC-50 values of 5 µM and 8 µM respectively. PGV-1 suppressed the cell growth permanently but not for sorafenib. Sorafenib did not change the cell cycle profiles on both cells, but PGV-1 arrested the cells at G2/M with the characteristic of senescent cells and mitotic disarrangement. PGV-1 and sorafenib showed the same effect in downregulating p-EGFR, indicating that both compounds have the same target on EGFR activation or as Tyrosine kinase inhibitors. PGV-1 suppressed the MYCN expression in HuH-6 and HLF cells but stabilized cMYC-T58 indicating that even though the MYCN was downregulated, the cells maintained the active form of cMYC. In this regard, PGV-1 also stabilized the expression of PLK-1 and AurA.

Conclusion

PGV-1 elicits stronger cytotoxic properties compared to sorafenib. The lower the MYCN expression, the higher the cytotoxic effect of PGV-1. PGV-1 abrogates cell cycle progression of both cells in mitosis through EGFR inhibition and stabilizes PLK-1 and AurA in correlation with the suppression of MYCN expression.

Interactions between oxidative stress and senescence in cancer: Mechanisms, therapeutic implications, and future perspectives

BACKGROUND

Recently, numerous studies have reported the interaction between senescence and oxidative stress in cancer. However, there is a lack of a comprehensive understanding of the precise mechanisms involved.

AIM

Therefore, our review aims to summarize the current findings and elucidate by presenting specific mechanisms that encompass functional pathways, target genes, and related aspects.

METHODS

Pubmed and Web of Science databases were retrieved to search studies about the interaction between senescence and oxidative stress in cancer. Relevant publications in the reference list of enrolled studies were also checked.

RESULTS

In carcinogenesis, oxidative stress-induced cellular senescence acts as a barrier against the transformation of stimulated cells into cancer cells. However, the senescence-associated secretory phenotype (SASP) is positively linked to tumorigenesis. In the cancer progression stage, targeting specific genes or pathways that promote oxidative stress-induced cellular senescence can suppress cancer progression. In terms of treatment, many current clinical therapies combine with novel drugs to overcome resistance and reduce side effects by attenuating oxidative stress-induced senescence. Notably, emerging drugs control cancer development by enhancing oxidative stress-induced senescence. These studies highlight the complacted effects of the interplay between oxidative stress and senescence at different cancer stages and among distinct cell populations. Future research should focus on characterizing the roles of distinct senescent cell types in various tumor stages and identifying the specific components of SASP.

CONCLUDSION

We've summarized the mechanisms of senescence and oxidative stress in cancer and provided illustrative figures to guide future research in this area.

Molecular Mechanism of Natural Food Antioxidants to Regulate ROS in Treating Cancer: A Review

Cancer is the second-highest mortality rate disease worldwide, and it has been estimated that cancer will increase by up to 20 million cases yearly by 2030. There are various options of treatment for cancer, including surgery, radiotherapy, and chemotherapy. All of these options have damaging adverse effects that can reduce the patient's quality of life. Cancer itself arises from a series of mutations in normal cells that generate the ability to divide uncontrollably. This cell mutation can happen as a result of DNA damage induced by the high concentration of ROS in normal cells. High levels of reactive oxygen species (ROS) can cause oxidative stress, which can initiate cancer cell proliferation. On the other hand, the cytotoxic effect from elevated ROS levels can be utilized as anticancer therapy. Some bioactive compounds from natural foods such as fruit, vegetables, herbs, honey, and many more have been identified as a promising source of natural antioxidants that can prevent oxidative stress by regulating the level of ROS in the body. In this review, we have highlighted and discussed the benefits of various natural antioxidant compounds from natural foods that can regulate reactive oxygen species through various pathways.