Scoparone induces autophagic cell death via the PAK1/AKT axis in colorectal cancer

Natural products target programmed cell death signaling mechanisms to treat colorectal cancer

As a highly prevalent gastrointestinal malignant tumor, colorectal cancer poses a serious challenge in terms of increasing morbidity and mortality and late diagnosis due to the invisibility of the disease. Although existing therapies are diverse but limited in efficacy, the mechanism of programmed cell death (PCD) has become a focus of research due to its central role in maintaining body homeostasis and regulating tumor progression. Multimodal cell death pathways, such as apoptosis, autophagy, pyroptosis and ferroptosis, have shown unique advantages in inhibiting the proliferation and migration of colorectal cancer cells and enhancing the sensitivity to chemotherapy by responding to internal and external environmental stimuli. In recent years, natural products have risen to prominence by virtue of their multi-target synergistic effects and chemo-sensitizing properties, and have opened up a new direction for colorectal cancer treatment by precisely regulating the PCD pathway. In this paper, we searched PubMed, Web of Science and CNKI databases for relevant studies in the last 10 years using the keywords (Colorectal cancer) and (programmed cell death) and natural products. This work retrieved 59 studies (55 from the past 5 years and 4 from the past 10 years) to reveal the mechanism of action of natural products targeting PCD, aiming to provide theoretical support and practical guidance for the optimization of clinical therapeutic strategies and the development of innovative drugs.

A novel PAK1/TCF1 regulatory axis promotes non-small cell lung cancer progression

BACKGROUND

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death, necessitating the identification of novel therapeutic targets. P21-activated kinases-1 (PAK1) plays a crucial role in oncogenesis, including NSCLC. Recent findings have elucidated T cell factor 1 (TCF1) as an anti-tumour factor, influencing T cell biology. However, the precise mechanism by which PAK1 promotes NSCLC progression via TCF1 regulation remains unclear.

METHODS

We collected 23 pairs of NSCLC tissue samples and obtained NSCLC RNA sequencing data and corresponding clinicopathologic information from The Cancer Genome Atlas (TCGA). Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) assessed PAK1 and TCF1 expression in NSCLC tissues and cells. Gain and loss-of-function experiments evaluated PAK1 and TCF1 effects on cell proliferation, invasion, migration, and apoptosis in vitro. Mechanistically, western blot (WB) and immunoprecipitation analysis evaluated the interaction between PAK1 and TCF1 in NSCLC. Finally, we assessed the clinical prognostic, disease progression, and immunotherapy response of PAK1 and TCF1 and their correlation with immune cell infiltration, immune checkpoint inhibitors (PD1, PDL1).

RESULTS

PAK1 expression was elevated in NSCLC tissues and cells, while TCF1 was significantly downregulated. PAK1 expression showed a significant inverse correlation with TCF1 mRNA in NSCLC. Silencing PAK1 (using shRNAs) and inhibiting PAK1 with the small molecule IPA-3 suppressed NSCLC cell malignancy in a dose-dependent manner, upregulating TCF1 expression, and vice versa. TCF1 amplification with the small molecule (TWS119) inhibited NSCLC cell proliferation, migration, and invasion in a dose-dependent manner without affecting PAK1 expression. Immunoprecipitation analysis confirmed PAK1 and TCF1 interaction in NSCLC. Joint survival analysis indicated that high PAK1 and low TCF1 expression were associated with unfavourable survival in patients with NSCLC. Lastly, the TCF1 was significantly correlated with immune cell infiltration [CD8+ T cell, and tumor infiltrating lymphocytes (TILs)], immune checkpoint inhibitors (PD1, PDL1), and can accurately predict the immunotherapeutic response.

CONCLUSION

This study demonstrates, for the first time, that PAK1 negatively regulates TCF1, contributing to NSCLC pathogenesis. The PAK1/TCF1 regulatory axis emerges as a critical determinant of carcinogenesis and a promising therapeutic target for NSCLC.

Osthole induces accumulation of impaired autophagosome against pancreatic cancer cells

Pancreatic cancer (PC) is one of the most aggressive malignancies worldwide, and few effective therapeutics are available. Osthole (OST), a natural coumarin, has been proven to be a potential anticancer compound. In this study, we found that OST significantly inhibited PC growth both in vitro and in vivo. Notably, the anti-PC effect of OST is mediated by excessive autophagosome accumulation and consequent apoptosis in PC cells. Mechanistically, OST increased the number of autophagosomes via two pathways. First, OST induced autophagy initiation by suppressing the Akt/mTOR signaling pathway. Second, OST induced autophagic arrest by blocking autophagosome-lysosome fusion. Consistently, inhibition of autophagy initiation restored PC cell growth, whereas autophagic flux inhibitors exacerbated the antitumor effect of OST in PC cells, suggesting a cytotoxic role of OST-induced autophagosome accumulation. In addition, we found that OST upregulates the expression of activating transcription factor 3 (ATF3), resulting in inactivation of the Akt/mTOR signaling pathway and autophagy initiation in PC cells. ATF3 overexpression increased the activation of autophagy, and inhibition of ATF3 expression decreased autophagy. Taken together, our study provides new insights into the OST-induced growth inhibitory effect on PC cells, suggesting a promising potential therapeutic role of OST for PC treatment.

Chinese Medicine in Colorectal Cancer Treatment: From Potential Targets and Mechanisms to Clinical Application

Colorectal cancer (CRC) is a global health challenge necessitating innovative therapeutic strategies. There is an increasing trend toward the clinical application of integrative Chinese medicine (CM) and Western medicine approaches. Chinese herbal monomers and formulations exert enhanced antitumor effects by modulating multiple signaling pathways in tumor cells, including inhibiting cell proliferation, inducing apoptosis, suppressing angiogenesis, reversing multidrug resistance, inhibiting metastasis, and regulating immunity. The synergistic effects of CM with chemotherapy, targeted therapy, immunotherapy, and nanovectors provide a comprehensive framework for CRC treatment. CM can mitigate drug toxicity, improve immune function, control tumor progression, alleviate clinical symptoms, and improve patients' survival and quality of life. This review summarizes the key mechanisms and therapeutic strategies of CM in CRC, highlighting its clinical significance. The potential for CM and combination with conventional treatment modalities is emphasized, providing valuable insights for future research and clinical practice.

Scoparone attenuates PD-L1 expression in human breast cancer cells by MKP-3 upregulation

Breast cancer is a frequently occurring malignant tumor that is one of the leading causes of cancer-related deaths in women worldwide. Monoclonal antibodies that block programed cell death 1 (PD-1)/programed cell death ligand 1 (PD-L1) - a typical immune checkpoint - are currently the recommended standard therapies for many advanced and metastatic tumors such as triple-negative breast cancer. However, some patients develop drug resistance, leading to unfavorable treatment outcomes. Therefore, other approaches are required for anticancer treatments, such as downregulation of PD-L1 expression and promotion of degradation of PD-L1. Scoparone (SCO) is a bioactive compound isolated from Artemisia capillaris that exhibits antitumor activity. However, the effect of SCO on PD-L1 expression in cancer has not been confirmed yet. This study aimed to evaluate the role of SCO in PD-L1 expression in breast cancer cells in vitro. Our results show that SCO downregulated PD-L1 expression in a dose-dependent manner, via AKT inhibition. Interestingly, SCO treatment did not alter PTEN expression, but increased the expression of mitogen-activated protein kinase phosphatase-3 (MKP-3). In addition, the SCO-induced decrease in PD-L1 expression was reversed by siRNA-mediated MKP-3 knockdown. Collectively, these findings suggest that SCO inhibited the expression of PD-L1 in breast cancer cells by upregulating MKP-3 expression. Therefore, SCO may serve as an innovative combinatorial agent for cancer immunotherapy.