Aiduqing formula suppresses breast cancer metastasis via inhibiting CXCL1-mediated autophagy

Xie-Bai-San increases NSCLC cells sensitivity to gefitinib by inhibiting Beclin-1 mediated autophagosome formation

BACKGROUND

Autophagy, a cellular process involving lysosomal self-digestion, plays a crucial role in recycling biomolecules and degrading dysfunctional proteins and damaged organelles. However, in non-small cell lung cancer (NSCLC), cancer cells can exploit autophagy to survive metabolic stress and develop resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), which reduce treatment efficacies. Currently, most studies have found that late-stage autophagy inhibitors can hinder EGFR-TKIs resistance, while research on early-stage autophagy inhibitors is still limited.

PURPOSE

This study investigates the mechanism via which the Xie-Bai-San (XBS) formula enhances NSCLC cell sensitivity to gefitinib, revealing the relationship between XBS-induced cell death and the inhibition of autophagosome formation.

METHODS

Cell viability was assessed using CCK-8 and EdU assays, lentivirus transfection was utilized to generate PC9 cells harboring the PIK3CA E545K mutation (referred to as PC9-M), autophagic flux was monitored using mCherry-GFP-LC3 adenovirus. Protein expression and colocalization were observed through immunofluorescence staining. The interaction between Bcl-2 and Beclin-1 in PC9-GR and PC9-M cells was determined via co-immunoprecipitation (Co-IP) assay, cell apoptosis was assessed by flow cytometry and PI staining, and overall survival analysis of lung adenocarcinoma patients was conducted using the TCGA database. In vivo experiments included a patient-derived xenograft (PDX) model with EGFR and PIK3CA mutations and subcutaneous mice xenografts of NSCLC cell lines (PC9 and PC9-GR). In addition, autophagic vesicles in mouse tumor tissues were observed via transmission electron microscopy analysis.

RESULTS

XBS effectively inhibits the proliferation of gefitinib-resistant NSCLC cells and induces apoptosis both in vitro and in vivo. Mechanistically, XBS suppresses gefitinib-induced autophagic flux by inhibiting autophagy through the upregulation of p-mTOR and Bcl-2 and downregulation of Beclin-1. Additionally, XBS enhances the interaction between Bcl-2 and Beclin-1, and the overexpression of Beclin-1 promotes NSCLC cell proliferation and counteracts XBS-induced cell death, while XBS demonstrates minimal impact on autophagosome-lysosome fusion or lysosome function.

CONCLUSION

This study reveals a novel role for the XBS formula in impeding autophagy initiation and demonstrates its potential as a candidate drug to counteract autophagy-induced treatment resistance in NSCLC.

Research progress of exosomes in drug resistance of breast cancer

Since breast cancer is a heterogeneous disease, there are currently a variety of treatment methods available, including chemotherapy, endocrine therapy, molecular targeted therapy, immunotherapy, radiation therapy, etc. Breast cancer recurrence and metastasis, despite many treatment modalities, constitute a considerable threat to patients' survival time and pose a clinical challenge that is difficult to tackle precisely. Exosomes have a very special and crucial role in the treatment of drug resistance in breast cancer as a carrier of intercellular communication in the tumor microenvironment. Exosomes and breast cancer treatment resistance have been linked in a growing number of clinical investigations in recent years. This paper covers the status of research on exosomes in the treatment of breast cancer drug resistance and offers theoretical guidance for investigating new strategies to treat breast cancer drug resistance.

CXCL1 promotes immune escape in colorectal cancer by autophagy-mediated MHC-I degradation

BACKGROUND

Immunotherapy is now seen as a potential remedy for colorectal cancer (CRC). Chemokines play a crucial role in tumors, including CRC, which contains CXCL1. We attempted to study how CXCL1 impacts immune escape in CRC.

METHODS

Bioinformatics analysis was used to examine CXCL1 level in CRC. qRT-PCR was used to assess CXCL1 and MHC-I (HLA-A, B, C) levels. Cell Counting Kit-8 (CCK-8) was used to measure cell viability. Cytotoxicity assay kit was utilized to assay CD8+ T cell cytotoxicity against CRC. Flow cytometry tested proliferation and apoptosis of CD8+ T cells. Chemotaxis assay evaluated chemotaxis of CD8+ T cells towards CRC. Immunofluorescence examined expression of autophagy marker LC3 and localization of NBR1/MHC-I. Western blot analysis measured protein levels of chemokines CXCL9 and CXCL10, autophagy-related proteins LC3-I and LC3-II, and MHC-I (HLA-A, B, C).

RESULTS

Bioinformatics analysis and qRT-PCR presented that CXCL1 was upregulated in CRC. Cell experiments demonstrated that CXCL1 overexpression promoted immune escape in CRC. Rescue experiments revealed that the autophagy inducer Rapa could attenuate the inhibitory effect of CXCL1 low expression on immune escape in CRC. Further studies showed that CXCL1 promoted immune escape in CRC by autophagy-mediated MHC-I degradation.

CONCLUSION

CXCL1 promoted immune escape in CRC by autophagy-mediated MHC-I degradation, suggesting that CXCL1 may be a possible immunotherapeutic target for CRC.

Long non-coding RNA MIDEAS-AS1 inhibits growth and metastasis of triple-negative breast cancer via transcriptionally activating NCALD

BACKGROUND

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with higher aggressiveness and poorer outcomes. Recently, long non-coding RNAs (lncRNAs) have become the crucial gene regulators in the progression of human cancers. However, the function and underlying mechanisms of lncRNAs in TNBC remains unclear.

METHODS

Based on public databases and bioinformatics analyses, the low expression of lncRNA MIDEAS-AS1 in breast cancer tissues was detected and further validated in a cohort of TNBC tissues. The effects of MIDEAS-AS1 on proliferation, migration, invasion were determined by in vitro and in vivo experiments. RNA pull-down assay and RNA immunoprecipitation (RIP) assay were carried out to reveal the interaction between MIDEAS-AS1 and MATR3. Luciferase reporter assay, Chromatin immunoprecipitation (ChIP) and qRT-PCR were used to evaluate the regulatory effect of MIDEAS-AS1/MATR3 complex on NCALD.

RESULTS

LncRNA MIDEAS-AS1 was significantly downregulated in TNBC, which was correlated with poor overall survival (OS) and progression-free survival (PFS) in TNBC patients. MIDEAS-AS1 overexpression remarkably inhibited tumor growth and metastasis in vitro and in vivo. Mechanistically, MIDEAS-AS1 mainly located in the nucleus and interacted with the nuclear protein MATR3. Meanwhile, NCALD was selected as the downstream target, which was transcriptionally regulated by MIDEAS-AS1/MATR3 complex and further inactivated NF-κB signaling pathway. Furthermore, rescue experiment showed that the suppression of cell malignant phenotype caused by MIDEAS-AS1 overexpression could be reversed by inhibition of NCALD.

CONCLUSIONS

Collectively, our results demonstrate that MIDEAS-AS1 serves as a tumor-suppressor in TNBC through modulating MATR3/NCALD axis, and MIDEAS-AS1 may function as a prognostic biomarker for TNBC.

The Role of Autophagy in Breast Cancer Metastasis

Patient morbidity and mortality is significantly increased in metastatic breast cancer. The metastasis process of breast cancer is very complicated and is delicately controlled by various factors. Autophagy is one of the important regulatory factors affecting metastasis in breast cancer by engaging in cell mobility, metabolic adaptation, tumor dormancy, and cancer stem cells. Here, we discuss the effects of autophagy on metastasis in breast cancer and assess the potential use of autophagy modulators for metastasis treatment.

New Advances in Targeted Therapy of HER2-Negative Breast Cancer

Breast cancer has an extremely high incidence in women, and its morbidity and mortality rank first among female tumors. With the increasing development of molecular biology and genomics, molecular targeted therapy has become one of the most active areas in breast cancer treatment research and has also achieved remarkable achievements. However, molecular targeted therapy is mainly aimed at HER2-positive breast cancer and has not yet achieved satisfactory curative effect on HER2-negative breast cancer. This article describes the potential targets that may be used for breast cancer treatment from the aspects of PI3K/AKT signaling pathway, DDR, angiogenesis, the cell cycle, breast cancer stem cells, etc., and explores possible inhibitors for the treatment of HER2-negative breast cancer, such as PI3K inhibitors, AKT inhibitors and m-TOR inhibitors that inhibit the PI3K/AKT signaling pathway, small molecule tyrosine kinase inhibitors that restrain angiogenesis, CDK inhibitors, aurora kinase inhibitors and HDAC inhibitors that block cell cycle, as well as the drugs targeting breast cancer stem cells which have been a hit, aiming to provide a new idea and strategy for the treatment of HER2-negative breast cancer.

Aiduqing formula inhibits breast cancer metastasis by suppressing TAM/CXCL1-induced Treg differentiation and infiltration

Background

Metastasis represents the leading cause of death in patients with breast cancer. Traditional Chinese medicine is particularly appreciated for metastatic diseases in Asian countries due to its benefits for survival period prolongation and immune balance modulation. However, the underlying molecular mechanisms remain largely unknown. This study aimed to explore the antimetastatic effect and immunomodulatory function of a clinical formula Aiduqing (ADQ).

Methods

Naive CD4⁺ T cells, regulatory T cells (Tregs), and CD8⁺ T cells were sorted by flow cytometry. Then, breast cancer cells and these immune cells were co-cultured in vitro or co-injected into mice in vivo to simulate their coexistence. Flow cytometry, ELISA, qPCR, double luciferase reporter gene assay, and chromatin immunoprecipitation assay were conducted to investigate the immunomodulatory and antimetastatic mechanisms of ADQ.

Results

ADQ treatment by oral gavage significantly suppressed 4T1-Luc xenograft growth and lung metastasis in the orthotopic breast cancer mouse model, without noticeable hepatotoxicity, nephrotoxicity, or hematotoxicity. Meanwhile, ADQ remodeled the immunosuppressive tumor microenvironment (TME) by increasing the infiltration of tumor-infiltrating lymphocytes (TILs) and cytotoxic CD8⁺ T cells, and decreasing the infiltration of Tregs, naive CD4⁺ T cells, and tumor-associated macrophages (TAMs). Molecular mechanism studies revealed that ADQ remarkably inhibited CXCL1 expression and secretion from TAMs and thus suppressed the chemotaxis and differentiation of naive CD4⁺ T cells into Tregs, leading to the enhanced cytotoxic effects of CD8⁺ T cells. Mechanistically, TAM-derived CXCL1 promoted the differentiation of naive CD4⁺ T cells into Tregs by transcriptionally activating the NF-κB/FOXP3 signaling. Lastly, mouse 4T1-Luc xenograft experiments validated that ADQ formula inhibited breast cancer immune escape and lung metastasis by suppressing the TAM/CXCL1/Treg pathway.

Conclusions

This study not only provides preclinical evidence supporting the application of ADQ in inhibiting breast cancer metastasis but also sheds novel insights into TAM/CXCL1/NF-κB/FOXP3 signaling as a promising therapeutic target for Treg modulation and breast cancer immunotherapy.