VPB0759 - Cancer-associated fibroblasts promote venous thrombosis through C-type lectin-like receptor 2/podoplanin in 3LL lung cancer mouse model

Monday, July 11, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: Virtual

Presenting Author(s)

Toshiaki Shirai, PhD

Assistant Professor
Clinical and Laboratory Medicine, University of Yamanashi
Chuo, Yamanashi, Japan

Co-Author(s)

TS

Tomoyuki Sasaki

Associate Professor
Clinical and Laboratory medicine, University of Yamanashi
Chuo, Yamanashi, Japan
NT

Nagaharu Tsukiji

Senior Assistant Professor
Clinical and Laboratory medicine, University of Yamanashi
Chuo, Yamanashi, Japan
SO

Saori Ohishi

Assistant Professor
Clinical and Laboratory medicine, University of Yamanashi
Chuo, Yamanashi, Japan
RY

Ryohei Yokomori, MD

Ph.D student
Clinical and Laboratory Medicine, University of Yamanashi
Chuo, Yamanashi, Japan
KT

Katsuhiro Takano

Senior Assistant Professor
Clinical and Laboratory medicine, University of Yamanashi
Chuo, Yamanashi, Japan
Katsue Suzuki-Inoue, MD, PhD

Professor
Clinical and Laboratory medicine, University of Yamanashi
Chuo, Yamanashi, Japan

Background: Platelets play pathophysiological roles in cancer-associated thrombosis (CAT). One of the underlying mechanisms is the membrane protein podoplanin. Some types of tumor cells expressing podoplanin can induce platelet aggregation via the platelet activation receptor C-type lectin-like receptor 2 (CLEC-2).
In addition to tumor cells, cancer-associated fibroblasts (CAFs) also express podoplanin. CAFs are the most abundant cancer-stromal cells; they promote cancer progression through cell-cell interactions and release extracellular vesicles (EVs). However, the relationship between CAFs and platelets in CAT remains unstudied.

Aims: We investigate whether CAFs and their EVs potentially promote CAT in 3LL mouse lung cancer model.

Methods: Podoplanin expression in EVs purified from NIH/3T3 cell-conditioned medium and 3LL tumor was analyzed by immunoblotting. Mouse platelet aggregation was induced by NIH/3T3 cells and their EVs. Plasma podoplanin level was compared between healthy mice and 3LL-bearing mice. At the femoral vein, the time to occlusion after ferric chloride injury was measured in healthy mice and 3LL-bearing mice. Tumor-bearing mice were treated with rat anti-mouse CLEC-2 monoclonal antibody 2A2B10 or control rat IgG four days before ferric chloride injury.

Results: EVs purified from NIH/3T3 cell-conditioned medium and 3LL tumor presented podoplanin. NIH/3T3 cells and their EVs induced platelet aggregation in a CLEC-2 dependent manner. The 3LL-bearing mice showed increased podoplanin levels in plasma and a shortened time to occlusion compared to healthy mice. In the tumor-bearing state, antibody-induced CLEC-2 depletion extended the time to occlusion compared to control IgG-treated mice.

Conclusion(s): Podoplanin-expressing EVs released from CAFs impact circulating podoplanin levels, which promote venous thrombosis. Antiplatelet therapy targeting CLEC-2 may be effective in treating CAT mediated by podoplanin derived from CAFs as well as tumor cells.