The HGF/c-MET axis has long been recognized as a central oncogenic driver in lung cancer. When hepatocyte growth factor binds to the MET receptor tyrosine kinase, it triggers intracellular cascades that promote tumor cell proliferation, epithelial-to-mesenchymal transition, invasion, and metastasis. Aberrant MET activation, whether through gene amplification, exon 14 skipping mutations, or autocrine ligand production, is a well-documented mechanism of resistance to EGFR-targeted therapies in non-small cell lung cancer. MET inhibitors have been developed and approved for subsets of patients whose tumors harbor specific MET alterations, and these drugs can produce striking responses. Yet the review emphasizes that clinical outcomes have been inconsistent, and the authors contend that a purely gene-centric view of MET targeting fails to capture the full biological complexity of MET dependency in tumors.

The core argument of the review is that MET signaling operates within a spatially heterogeneous and dynamically regulated context. MET activity is not uniform across a tumor; instead, it varies from region to region, shaped by local metabolic states, interactions with stromal cells, and the co-activation of other oncogenic pathways. This spatial heterogeneity means that a biopsy taken from one part of a tumor may not reflect the signaling landscape elsewhere, and a treatment decision based on static genomic alterations alone may miss functionally important MET-driven states. The authors argue that emerging technologies, including spatial transcriptomics, single-cell profiling, and integrative metabolic assessments, are revealing that MET dependency is a multidimensional property that cannot be reduced to the presence or absence of a genomic alteration on a pathology report.

One of the most compelling aspects of the review is its synthesis of how MET signaling may contribute to the formation of localized immunosuppressive niches within tumors. The authors describe several converging mechanisms. MET activity appears to modulate glycolytic reprogramming, the metabolic shift by which cancer cells preferentially consume glucose and produce lactate even in the presence of oxygen. Lactate accumulation in the tumor microenvironment is well known to impair the function of cytotoxic T lymphocytes and natural killer cells, the immune cells responsible for killing tumor cells. By promoting lactate production, MET-driven tumors may create acidic microenvironments that exclude or disable the very immune cells that immunotherapies rely upon.

Beyond lactate, the review highlights adenosine signaling as another metabolic route through which MET may foster immune evasion. Adenosine accumulates in hypoxic and metabolically stressed tumor regions and, through its receptors on immune cells, exerts potent immunosuppressive effects, dampening T cell activity and promoting the expansion of regulatory immune populations. The authors suggest that MET signaling intersects with these purinergic metabolic pathways, potentially amplifying the immunosuppressive tone of the microenvironment in a spatially confined manner. In parallel, MET activity appears to influence the expression of immune checkpoint molecules such as PD-L1, the molecular brakes that tumors use to evade T cell attack. If MET signaling upregulates checkpoint expression in specific tumor niches, it could explain why immune checkpoint blockade, one of the great success stories of modern lung cancer treatment, fails in some patients despite apparently favorable biomarkers.

The review also draws attention to cancer-associated fibroblasts, or CAFs, as key architectural partners in MET-driven immune exclusion. These stromal cells are increasingly recognized as active participants in tumor progression, secreting growth factors, remodeling the extracellular matrix, and physically organizing the tumor into functional microdomains. The authors propose that MET signaling and CAF-mediated interactions cooperate to create localized pockets of immune suppression, where excluded T cells accumulate at the tumor periphery while the tumor core remains immunologically silent. This spatial organization has profound therapeutic implications, because a drug that works beautifully in one region of a tumor may be irrelevant in another where different signaling and metabolic conditions prevail.

What makes this synthesis particularly timely is the convergence of new profiling technologies that make such context-aware analysis feasible. Spatial transcriptomics allows researchers to map gene expression across intact tissue sections, preserving the architectural information that conventional bulk sequencing destroys. Single-cell RNA sequencing resolves the diversity of individual cells within a tumor, distinguishing malignant subclones, immune subsets, and stromal populations that would otherwise be averaged together. Integrative metabolic assessments add yet another layer, connecting gene expression to the biochemical states that govern immune cell function. Applied together, these tools can identify biologically coherent MET-driven tumor states, defined not just by genomic alterations but by the spatial, metabolic, and immune features that determine how a tumor actually behaves in a patient.

The therapeutic implications of this reframing are substantial. The authors argue that the field should move beyond a purely gene-centric view of MET targeting toward context-aware strategies. In practice, this could mean combining MET inhibitors with immunomodulatory agents, such as immune checkpoint blockers, to address the immune suppression that MET signaling helps establish. It could also mean pairing MET inhibition with metabolic interventions designed to counteract the glycolytic and adenosine-mediated mechanisms that create immunologically cold tumor niches. The logic is that targeting MET alone may dismantle one pillar of tumor fitness while leaving the spatially confined immune and metabolic defenses intact, whereas rational combinations could overcome resistance mechanisms that emerge from the microenvironment rather than from the cancer cell itself.

For patients with MET-driven lung cancer, the promise of such combination strategies is tempered by the challenges that always accompany biomarker-driven medicine. Defining which patients will benefit from MET inhibition, predicting who will respond to immunotherapy, and identifying the right combinations for the right tumor states all require biomarker frameworks far more sophisticated than those in current clinical use. The review’s proposal for multidimensional biomarkers that incorporate spatial, metabolic, and immune parameters represents an ambitious step in that direction. If validated, such frameworks could transform how oncologists select therapies, replacing single-gene tests with integrated profiles that capture the biological reality of each patient’s tumor. The path from this conceptual synthesis to clinical practice will require prospective studies, but the direction is clear: the future of MET-targeted therapy in lung cancer may depend less on the mutation a tumor carries and more on the landscape it creates around itself.

Subject of Research: The role of c-MET signaling in shaping the spatial and metabolic immune landscape of lung cancer

Article Title: Reprogramming the immune landscape in lung cancer: spatial and metabolic contexts of c-MET signaling

Article References: Zhu, D., & Zang, S. (2026). Reprogramming the immune landscape in lung cancer: spatial and metabolic contexts of c-MET signaling. Journal of Translational Medicine. https://doi.org/10.1186/s12967-026-08900-w

Image Credits: AI Generated

DOI: 10.1186/s12967-026-08900-w

Keywords: c-MET signaling, HGF, lung cancer, NSCLC, tumor microenvironment, immunometabolism, spatial transcriptomics, immune checkpoint blockade, cancer-associated fibroblasts, glycolytic reprogramming, lactate, targeted therapy

BPIFB1 is a member of the bactericidal permeability-increasing fold-containing family, a group of innate immune proteins whose members share a structural architecture evolved to bind lipids and engage microbial targets. The protein is abundantly expressed in the nasopharyngeal epithelium, the very tissue from which nasopharyngeal carcinoma arises, which makes its behavior in this cancer particularly consequential. According to the review, BPIFB1 is markedly downregulated in nasopharyngeal carcinoma tissues, and loss of its expression is associated with poor prognosis for patients. In other words, the more the molecule disappears from tumor cells, the worse the clinical outlook tends to be, a correlation that has prompted researchers to classify it as a tumor suppressor.

What makes the story compelling from a viral oncology standpoint is the mechanism behind that loss. The review highlights accumulating evidence that BPIFB1 is directly targeted and suppressed by EBV-encoded miR-BART4, one of the microRNAs the virus produces during latent infection. Epstein–Barr virus is known to maintain its long-term residence in infected cells in part by deploying a panel of BART microRNAs, which fine-tune both viral and host gene expression without provoking strong immune detection. By steering miR-BART4 at BPIFB1, the virus appears to strip the epithelium of one of its local sentinels, a maneuver that could undermine both the tissue’s barrier functions and its capacity to coordinate immune responses.

The authors frame BPIFB1 as a multi-node tumor suppressor, a description that captures the unusual breadth of its influence. Rather than acting through a single pathway, the molecule is implicated in regulating several of the classic hallmarks of cancer simultaneously. These include immune escape, the process by which tumor cells avoid recognition and destruction by cytotoxic lymphocytes; metastatic invasion, the acquisition of motile and tissue-infiltrating behavior that allows cancer cells to spread; and glycolytic reprogramming, the metabolic shift toward heightened glucose fermentation even in the presence of oxygen, known as the Warburg effect, which supports rapid proliferation.

The reach of BPIFB1 extends further still. The review identifies roles for the molecule in modulating radioresistance, a phenomenon of particular clinical relevance in nasopharyngeal carcinoma, where radiotherapy is a mainstay of treatment and tumor cells that withstand radiation drive treatment failure. BPIFB1 also appears to influence cell proliferation directly and to engage inflammation-associated signaling, including pathways centered on NF-kappaB, a transcription factor family that sits at the hub of inflammatory responses and is frequently co-opted in malignancy. Chronic inflammation in the tumor microenvironment is widely recognized as a driver of cancer progression, and a molecule capable of tempering those signals could in principle slow multiple aspects of tumor evolution at once.

An intriguing theme running through the review is that BPIFB1 does not behave identically in every tissue. The authors describe tissue-specific functional heterogeneity across multiple tumor types, citing evidence from breast, lung and gastric cancers in addition to nasopharyngeal carcinoma. This kind of context dependence is increasingly appreciated in cancer biology: a protein that suppresses growth in one epithelium may have more nuanced or even opposing effects elsewhere, depending on the local repertoire of interacting partners, signaling pathways and metabolic conditions. For researchers hoping to translate BPIFB1 findings into the clinic, this heterogeneity is a caution as well as an opportunity, since any therapeutic strategy would need to account for how the molecule behaves in the specific tissue being treated.

To situate these functional findings mechanistically, the review systematically summarizes the molecular structure of BPIFB1 and the regulatory mechanisms underlying its aberrant expression in cancer. The protein belongs to the PLUNC subfamily, which is expressed selectively in the upper airways and is thought to participate in the mucosal defense of these surfaces, contributing to the antimicrobial and anti-inflammatory properties of airway secretions. That lineage makes evolutionary sense of the molecule’s dual character: it is simultaneously an innate immune effector shaped for mucosal surveillance and, according to the evidence assembled by the Changsha team, a regulator of intracellular signaling circuits that tumors exploit for survival and spread.

Beyond cancer, the review casts a wider net, surveying recent advances in BPIFB1-related research across multi-system diseases. This broader framing reflects a growing recognition that innate immune molecules of the airway are not narrowly specialized anti-bacterial agents but participants in systemic biology, with potential relevance wherever epithelial barriers, mucosal immunity and inflammatory signaling intersect. The disease geography of nasopharyngeal carcinoma itself underscores the point, since the tight association between EBV and this tumor in specific populations suggests that host genetic and environmental factors modulating mucosal immunity may shape risk in ways that a single-virus, single-tissue perspective would miss.

On the translational front, the authors discuss BPIFB1’s potential as both a biomarker and a therapeutic target. As a biomarker, the molecule’s consistent downregulation in nasopharyngeal carcinoma and its association with poor prognosis suggest that measuring its expression could help stratify patients or track disease behavior. As a therapeutic target, the challenge is thornier, because restoring a suppressed tumor suppressor inside malignant cells is far more difficult than inhibiting an overactive oncogene. Yet the viral connection offers a conceptual foothold: if EBV-encoded miR-BART4 is the principal driver of BPIFB1 loss, strategies aimed at blunting that microRNA or counteracting its downstream effects could, in principle, reawaken the suppressed protein. The open-access review, which was published on 25 September 2026 and supported by the Project of Changsha Natural Science Foundation, does not claim such interventions exist today; it consolidates the mechanistic groundwork that would make them conceivable.

For a cancer that remains a major burden in Southern China and Southeast Asia, and for the broader field of virus-associated malignancy, the synthesis offered by Cai and colleagues is a reminder that the tumor microenvironment is shaped as much by what the immune system loses as by what the tumor gains. BPIFB1, a molecule of the airway’s first line of defense, emerges from this review as a lens through which viral manipulation, metabolic reprogramming, inflammatory signaling and immune evasion can be seen as a single connected story. Whether future work can convert that mechanistic insight into clinical tools, from prognostic assays to microRNA-targeted therapies, will depend on validating these roles across cohorts and disease settings, but the review makes a clear case that this underappreciated epithelial protein deserves a prominent place on the research agenda for nasopharyngeal carcinoma and beyond.

Subject of Research: Tumor-suppressive and immunomodulatory roles of BPIFB1/LPLUNC1 in nasopharyngeal carcinoma

Article Title: Tumor-suppressive and immunomodulatory roles of BPIFB1/LPLUNC1: mechanistic insights from nasopharyngeal carcinoma and implications for multi-system diseases

Article References: Cai, J., Jiang, F., Xiao, L., & Zhang, W. (2026). Tumor-suppressive and immunomodulatory roles of BPIFB1/LPLUNC1: mechanistic insights from nasopharyngeal carcinoma and implications for multi-system diseases. Cancer Immunology, Immunotherapy. https://doi.org/10.1007/s00262-026-04580-z

Image Credits: AI Generated

DOI: 10.1007/s00262-026-04580-z

Keywords: BPIFB1, LPLUNC1, nasopharyngeal carcinoma, Epstein-Barr virus, miR-BART4, tumor suppressor, immunomodulation, glycolytic reprogramming, radioresistance, NF-kappaB, innate immunity, multi-system diseases