CXCR4

CXCR4 (C-X-C chemokine receptor type 4)

一行要約

CXCR4 (2q22.1、HGNC:2561) は CXCL12 (SDF-1) を唯一のリガンドとする 7 回膜貫通型 GPCR で、HSC homing / リンパ球 trafficking / 神経発生 / 血管新生・腫瘍転移 organotropism に普遍的に関与する。SCLC・骨髄腫・乳腺・膠芽腫・腺癌で過剰発現し、骨髄・肝・肺の CXCL12-rich niche への metastatic seeding を駆動する。CXCR4 antagonist plerixafor が HSC 動員で承認、新規 oral 薬剤 mavorixafor が WHIM 症候群 (CXCR4 gain-of-function) で承認。68Ga-Pentixafor PET/CT が CXCR4 imaging biomarker として登場し、SCLC では SUVmax 平均 10.3 と高集積、¹⁷⁷Lu-Pentixather による theranostic strategy が前臨床で進展 (Liu et al. OncolRev 2026)。CNS 脳転移 TLS では CXCL12-CXCR4 軸 が TCF1+CD4+ T 細胞-microglia 相互作用の初期動員 chemokine として機能し、anti-PD-1 + CXCL12 で TLS 様構造を誘導 (Yu et al. EBioMedicine 2026)。

主要エビデンス

• CXCR4 PET imaging (68Ga-Pentixafor): SCLC で SUVmax 平均 10.3、NSCLC 腺癌 8.0・扁平 6.2、SCLC vs NSCLC 鑑別 sens 85.7% / spec 78.1%。¹⁸F-FDG で見逃した脳転移検出例も (Liu et al. OncolRev 2026)
• Theranostic ¹⁷⁷Lu-Pentixather: SCLC 前臨床で抗 PD-1 と相乗効果、CXCR4 RLT (radioligand therapy) が SCLC NEC の新規モダリティとして開発
• CNS TLS の CXCL12-CXCR4 axis Yu et al. EBioMedicine 2026: NSCLC 脳転移 120 例で TLS+ 43% (全て E-TLS) が OS / iPFS / ICI 応答の独立予測因子。TCF1+CD4+ T 細胞 (LTi 様) と TMEM119+ microglia (LTo 様) の相互作用が CXCL12-CXCR4 軸で開始、anti-PD-1 + rmCXCL12 が LTβR 依存で TLS 様構造を誘導
• HSC mobilization: plerixafor (AMD3100) が autologous HSCT で G-CSF 併用承認 (multiple myeloma / NHL)
• WHIM 症候群: CXCR4 truncating mutation (gain-of-function) で warts / hypogammaglobulinemia / infection / myelokathexis、mavorixafor で承認
• Metastasis organotropism: Muller 2001 (Nature) が乳癌で CXCR4 → CXCL12 niche (肺・骨髄・肝・リンパ節) への組織指向性を初報告。Hoshino et al. Nature 2015 系列の exosome organotropism と並ぶ転移 niche concept の柱

メカニズム

• CXCL12 (SDF-1α/β) との結合: 唯一のリガンドとして高親和性結合。CXCR7/ACKR3 が “decoy receptor” として CXCL12 を sequester し、CXCR4 signaling を調節
• 下流 signaling: Gαi → cAMP 抑制 / Gβγ → PI3K-AKT / PLCβ-IP3/DAG → Ca²⁺ flux / RhoA → cytoskeletal rearrangement → migration / chemotaxis
• β-arrestin 経路: receptor internalization と MAPK-ERK signaling の bias
• Niche localization の分子基盤:
• 骨髄: CAR (CXCL12-abundant reticular) cell が CXCL12 産生 → HSC retention
• 肝: hepatic stellate / endothelial cell が CXCL12 産生 → transmigration
• CNS: microglia / astrocyte が CXCL12 産生 → T 細胞 / TLS 形成促進
• 腫瘍細胞での CXCR4 過剰発現の driver: HIF-1α 誘導 (hypoxia) / NF-κB / VEGF feedback / oncogenic signaling (KRAS / MYC)

臨床位置づけ

• 承認 / 開発薬剤: plerixafor (HSC mobilization)・mavorixafor (WHIM)・ulocuplumab (multiple myeloma 開発)・balixafortide (TNBC Phase III 失敗)・motixafortide (NCT04246398、myeloma)
• イメージング・治療: 68Ga-Pentixafor PET → SCLC / NEC / 多発性骨髄腫 staging、¹⁷⁷Lu-Pentixather による RLT theranostic
• 免疫治療併用: CXCR4 阻害 + anti-PD-(L)1 の Phase 1/2 が複数進行 (microsatellite-stable CRC, PDAC, melanoma)。Niche modification → T 細胞 trafficking 促進が rationale
• CNS-active な脳転移戦略: Yu et al. EBioMedicine 2026 の anti-PD-1 + CXCL12 induction strategy は対極的 (受容体阻害でなく ligand 供給) で、TLS 形成促進 → CNS 免疫制御を狙う新規アプローチ

Open Questions

• CXCR4 阻害 vs CXCL12 augmentation の使い分け: 全身性 metastasis 抑制では阻害、CNS TLS 誘導では augment が必要となる文脈依存性
• CXCR7 / ACKR3 dual targeting: decoy receptor も同時に targetingして CXCL12 gradient を controlled に調整できるか
• CXCR4 RLT の正常組織毒性: 骨髄・腸管 CXCR4+ stem niche への off-target radiation exposure
• Combination optimal sequencing: anti-PD-(L)1 + CXCR4 inhibitor の dose / timing
• PET-guided patient selection: 68Ga-Pentixafor SUV cut-off の standardization
• HIV co-receptor 機能との bridging: CXCR4 は HIV X4-tropic virus の co-receptor。免疫抑制下の opportunistic infection 影響

関連エンティティ

• 関連経路: Neutrophil-recruitment-activation-pathway / PI3K-AKT-mTOR-pathway / NF-kB-pathway / VEGF-angiogenesis-pathway
• 関連サイトカイン: CXCL12 (唯一の ligand)
• 関連薬剤: PD-1-inhibitor / PD-L1-inhibitor
• 関連細胞種: CD8-T-cell / CD4-T-helper-cell / Microglia / Neutrophil-TAN / MDSC / Circulating-tumor-cell / Mesenchymal-stem-cell
• 関連手法: Radiomics (PET imaging context)
• 関連概念: Pre-metastatic-niche / Brain-met-pre-metastatic-niche / Leptomeningeal-metastasis / Tertiary-lymphoid-structure / Cancer-dormancy

関連論文

直近 30 件のみ表示中 (関連 113 件)。 全件は MOC ページ または Obsidian (source Markdown) から辿れます。

Basic-Brain metastasis

• Liu et al. CancerDiscov 2026 — GPNMB drives brain metastasis by sculpting a pathological endothelial-immune interactome
• Yu et al. EBioMedicine 2026 — Tcf1+cd4+ t cells and microglia co-orchestrate tertiary lymphoid structures to enhance prognosis and immunotherapy in
• Dunbar et al. TrendsCancer 2025 — Regulation of metastatic organotropism

Basic-Extracellular vesicles

• Zhang et al. CellRepMed 2026 — Artificial exosomes synergistically reshape sepsis immune homeostasis by modulating neutrophil fate and blocking
• Pontis et al. JExpClinCancerRes 2026 — Circulating extracellular vesicles from early-stage lung cancer patients trigger endothelial activation to drive

Basic-Immunotherapy

• Brennan et al. CellRepMed 2026 — Circulating natural killer cells are phenotypically and functionally altered in age-related macular degeneration
• Pei et al. Immunity 2026 — Neutrophil regulation of immunotherapy for cancer is controlled by type II interferon
• Kim et al. NatImmunol 2026 — Engineering NK and T cells with metabolite-sensing receptors to target solid tumors

Basic-Neutrophil and myeloid cell

• Wang et al. ACSApplMaterInterfaces 2025 — Neutrophil-mediated tumor discrimination biomimetic nanodevice for precise tumor eradication and metastasis cascade
• Qian et al. CancerCell 2025 — A CXCR4 partial agonist improves immunotherapy by targeting immunosuppressive neutrophils and cancer-driven
• Ballesteros et al. Cell 2025 — The neutrophil collective
• Gao et al. CellMetab 2026 — Restricting lipid accumulation in tumor-infiltrating neutrophils mediates caloric restriction-induced anti-cancer
• Koenderman et al. CellMolImmunol 2025 — Neutrophils in cancer from biology to therapy
• Ng et al. Immunity 2025 — From complexity to consensus A roadmap for neutrophil classification
• Lin et al. JImmunotherCancer 2026 — Integrin CD11bCD18 reprograms macrophage polarization by suppressing ERKSTAT3 signaling to enhance antitumor immunity
• Kusch et al. Science 2026 — Platelet-derived integrin-and tetraspanin-enriched tethers exacerbate severe inflammation
• Zhou et al. SignalTransductTargetTher 2025 — Therapeutic potential of tumor-associated neutrophils dual role and phenotypic plasticity

Basic-Others

• Quail et al. Cell 2026 — Cancer ecosystems a dynamic interplay across scales
• Chen et al. JImmunotherCancer 2026 — Targeting CD74 may mitigate immune-escape features and enhance BCMA CAR-T activity in preclinical models of
• Leunig et al. NatRevImmunol 2025 — Connection and communication between the nervous and immune systems
• Lee et al. Neuron 2026 — Immune-brain plasticity underpins stress and affective behaviors
• Liu et al. OncolRev 2026 — Progress in the application of 68ga-pentixafor petct in lung cancer a review
• Li et al. ProcNatlAcadSciUSA 2025 — Targeting orthotopic and metastatic pancreatic cancer with allogeneic stem cell-engineered mesothelin-redirected

Basic-Tumor microenvironment

• Liu et al. CancerCell 2026 — Molecular phenotypes and spatial archetypes A new framework for cancer-associated fibroblasts
• Mahadevan et al. CancerCell 2026 — Tumor-restraining fibroblasts emerge after chemotherapy specifically in responders
• Eigenbrood et al. CancerRes 2025 — Spatial profiling identifies regionally distinct microenvironments and targetable immunosuppressive mechanisms in
• Subudhi et al. Cell 2026 — Targeting angiogenesis lessons from 25 years of normalizing tumor vasculature
• Zhang et al. Cell 2026 — Uncovering spatially resolved functional genomics with CRISPR screen sequencing
• Garate-Soraluze et al. JImmunotherCancer 2026 — Cancer-associated fibroblast targeting therapies as a tool to enhance responses to radiotherapy and immunotherapy

Clinical-SCLC

• Campisi et al. CancerCell 2026 — Vascular STING activation facilitates NK cell anti-tumor immunity in small cell lung cancer