Deciphering the Key Axis of PTMC Progression via Single-Cell and Spatial Transcriptomics: ANT BIO PTE. LTD. Multiplex Fluorescence Kit Empowers Protein Localization Research

Recently, a landmark study on the progression mechanism of papillary thyroid microcarcinoma (PTMC) was published in Advanced Science (2025). A team from China Medical University, using multi-technical approaches including single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics, first identified the PROS1-MERTK axis as the core pathway driving the crosstalk of the PTMC microenvironment and disease progression. In the critical validation phase of protein expression and colocalization, the research team selected the Multiplex Fluorescence Immunohistochemistry Kit from ANT BIO PTE. LTD. (Catalog No.: abs50014), successfully achieving precise visualization of multiple target proteins and providing direct evidence for mechanism elucidation.

1. Literature Information

Title: PROS1‐MERTK Axis Drives Tumor Microenvironment Crosstalk and Progression in Papillary Thyroid Microcarcinoma

Journal: Advanced Science (Impact Factor: 14.1)

DOI: https://doi.org/10.1002/advs.202413474

Core Reagent from ANT BIO PTE. LTD.: 6-Color Multiplex Fluorescence Immunohistochemistry Staining Kit (Mouse/Rabbit Universal Secondary Antibody) (Catalog No.: abs50014)

2. Research Background: Clinical Pain Points of PTMC Urgently Need Mechanistic Breakthroughs

The incidence of papillary thyroid carcinoma (PTC) is increasing year by year, among which papillary thyroid microcarcinoma (PTMC, diameter ≤ 1cm) accounts for more than 50%. Although most PTMC grow slowly with a favorable prognosis (10-year survival rate of 93.5%-97%), 0.4%-28.8% of cases still experience rapid progression (such as tumor enlargement, lymph node metastasis, and extrathyroidal invasion). Clinically, there is a lack of biomarkers and intervention targets for accurately identifying progression risks.

In addition, since the concept of "overdiagnosis and overtreatment of PTMC" was proposed in 2013, countries such as Japan and the United States have promoted "active surveillance (AS)" instead of surgery. However, distinguishing "indolent PTMC" from "progressive PTMC" remains a clinical challenge—which is exactly the core goal of this study: to explore the key molecular mechanisms and potential biomarkers of PTMC progression.

3. Core Research Ideas: Systematic Analysis from "Cellular Ecology" to "Pathway Mechanism"

The research team adopted a logical chain of "multi-dimensional sequencing + multi-level validation" to progressively reveal the mechanism of PTMC progression. The specific ideas are as follows:

3.1 Sample Design: Covering All Stages of the Disease to Ensure Data Representativeness

Nineteen surgical specimens (from 15 patients) were selected, covering 4 key groups:

•         Normal thyroid tissue (4 cases);

•         Non-progressive PTMC (4 cases, no progression after 5 years of AS);

•         Progressive PTMC (5 cases, with tumor enlargement/metastasis);

•         Progressive PTC (6 cases, advanced cases).

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3.2 Technical Route: Three-Step Process of "Sequencing Analysis→Spatial Localization→Functional Verification"

•         Single-cell level: scRNA-seq was performed on 146,529 cells, dividing them into 32 cell clusters, and clarifying the dynamic changes of 6 major cell types such as thyroid cancer cells, fibroblasts, and immune cells;

•         Spatial level: Combined with 10x Visium spatial transcriptomics to locate the distribution of different cell populations in tissues and analyze the heterogeneity of advanced tumors;

•         Communication level: CellChat was used to analyze intercellular ligand-receptor interactions, identifying the PROS1-MERTK axis as the key pathway;

•         Protein validation level: The Multiplex IHC/IF Kit from ANT BIO PTE. LTD. (abs50014) was used to detect the expression and colocalization of target proteins, verifying the cellular origin of the pathway;

•         Functional validation level: Cell migration/invasion experiments and mouse subcutaneous xenograft models were used to confirm the progression-promoting effect of the PROS1-MERTK axis;

•         Mechanism exploration level: SCENIC analysis and dual-luciferase reporter assay were used to identify the transcription factors (NFYB/FOXP2) regulating PROS1 and the downstream pathways (WNT/TGF-β).

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4. Key Research Results: The PROS1-MERTK Axis is the "Accelerator" of PTMC Progression

Through systematic analysis, the research team drew 4 core conclusions, each supported by solid data:

4.1 PTC Progression is Accompanied by "Immunosuppression + Fibroblast Enrichment" in the Microenvironment

scRNA-seq results showed that:

•         With disease progression (normal→Stage I→Stage II→Stage III), the proportion of T/NK cells gradually decreased (enhanced immunosuppression);

•         The proportion of fibroblasts increased significantly (from about 5% in normal tissues to 18% in Stage III), becoming the core "signal senders" in the microenvironment.

4.2 The PROS1-MERTK Axis is the "Key Hub" of Cellular Communication

Analysis of intercellular ligand-receptor interactions via CellChat revealed that:

•         PROS1 (ligand) is mainly secreted by "adipogenic cancer-associated fibroblasts (adi-CAFs)" in the progressive stage;

•         MERTK (receptor) is mainly expressed in advanced tumor cells and myeloid cells (such as tumor-associated macrophages);

•         The interaction intensity increased significantly with progression (normal < Stage I < Stage II ≤ Stage III), and promoted progression through two modes: paracrine (CAFs→tumor cells) and autocrine (tumor cells autocrine PROS1).

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4.3 NFYB/FOXP2 Regulates PROS1 Transcription as the "Upstream Switch" of the Pathway

SCENIC transcription factor analysis and dual-luciferase experiments confirmed that:

•         In fibroblasts, NFYB and FOXP2 can directly bind to the PROS1 promoter and activate its transcription;

•         After knocking down NFYB/FOXP2, the mRNA and protein expressions of PROS1 decreased by more than 60%, and the migration ability of tumor cells was significantly weakened.

4.4 PROS1-MERTK Promotes Progression via the WNT/TGF-β Pathway, and MERTK Can Serve as a Biomarker

Western blot and GSEA analysis confirmed that:

•         After PROS1 binds to MERTK, it activates the downstream WNT/β-catenin and TGF-β/SMAD2 pathways, promoting tumor cell proliferation and invasion;

•         Verification via the TCGA database: MERTK is highly expressed in progressive PTMC/PTC, and patients with high expression have a poorer prognosis (disease-free survival shortened by 35%), suggesting that MERTK can serve as a potential biomarker and therapeutic target for PTMC progression.

5. Product Empowerment by ANT BIO PTE. LTD.: Multiplex Fluorescence Kit Solves the "Protein Localization Dilemma"

In the entire study, "the cellular origin of PROS1" and "the tissue localization of PROS1-MERTK" are key scientific issues, and the Multiplex IHC/IF Kit from ANT BIO PTE. LTD. (Catalog No.: abs50014) is the core tool to solve this problem.

5.1 Product Information and Application Scenarios

5.2 Specific Role in the Study: Directly Verifying That "adi-CAFs Are the Main Source of PROS1"

The research team used the abs50014 kit to perform multiplex immunofluorescence staining on tissue sections at different stages, obtaining key evidence:

•         Staining targets: ACTA2 (fibroblast marker, red), PROS1 (green), DAPI (nucleus, blue);

•         Results: In normal tissues and non-progressive PTMC, there was almost no colocalization between ACTA2+ fibroblasts and PROS1; while in progressive PTMC (Stage II) and PTC (Stage III), more than 80% of ACTA2+ fibroblasts expressed PROS1 simultaneously (the overlap rate of red and green signals > 75%), directly confirming that adi-CAFs are the main secretory cells of PROS1.

In addition, the kit was also used to verify the tissue expression differences of PROS1 and MERTK: in the tumor area of advanced tissues, the fluorescence signal intensities of PROS1 and MERTK were 3-5 times higher than those in normal tissues, further confirming the correlation between the activation of this axis and disease progression.

6. Summary and Outlook: The "Bridge" from Basic Research to Clinical Translation

This study not only first revealed the core role of the PROS1-MERTK axis in PTMC progression, providing "MERTK" as a potential biomarker and therapeutic target for clinical practice, but also demonstrated the powerful value of the research paradigm of "single-cell + spatial transcriptomics + multiplex fluorescence verification" in the field of cancer microenvironment.

As a key verification tool, the Multiplex IHC/IF Kit (abs50014) from ANT BIO PTE. LTD., with its advantages of high specificity and multi-channel compatibility, provided reliable support for the cross-scale mechanism elucidation of "protein-cell-tissue". In the future, ANT BIO PTE. LTD. will continue to launch more high-quality scientific research tools to assist more research breakthroughs in the fields of cancer microenvironment and precision medicine, and provide solid technical guarantee for clinical translation.

7. Brand Mission

As a professional supplier of life science reagents, ANT BIO PTE. LTD. is dedicated to providing high-quality, reliable products and comprehensive solutions to empower global life science research. The company's three specialized sub-brands—Absin focusing on general reagents and kits, Starter on antibodies, and UA on recombinant proteins—cover the full spectrum of research needs in the life science field. Our core mission is to bridge the gap between cutting-edge scientific research and practical applications, accelerate the pace of scientific discovery, and contribute to the advancement of human health and regenerative medicine.

8. Recommended Multiplex Fluorescence Immunohistochemistry Kits from ANT BIO PTE. LTD.

More Multiplex Immunofluorescence IHC Kits

9. Disclaimer

This article is AI-compiled and interpreted based on the original work in DOI: 10.1002/advs.202413562. All intellectual property (e.g., images, data) of the original publication shall belong to the journal and the research team. For any infringement, please contact us promptly and we will take immediate action.

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