Non-small cell lung cancers, particularly squamous cell carcinoma and adenocarcinoma subtypes, have long posed a staggering challenge for oncologists. While immunotherapy has revolutionized treatment paradigms in recent years, a substantial fraction of patients either fails to respond or eventually develops resistance, underscoring the urgent need for novel approaches. The OSUCCC – James team focused their investigation on the lysosome, a cellular organelle integral to maintaining cellular equilibrium through nutrient recycling and metabolic regulation, and a protein known as SREBP-1, a master regulator of lipid and glucose metabolism within tumor cells.

Previous attempts to suppress tumor growth through lysosomal inhibition — employing drugs such as chloroquine (CQ) — have yielded only modest success. Such therapies aim to disrupt the tumor’s metabolic adaptability by impairing lysosome activity, thereby limiting nutrient access necessary for unchecked proliferation. However, tumors have consistently demonstrated an uncanny ability to circumvent such interventions, maintaining metabolic fluxes and promoting survival despite therapeutic pressure. This study provides the first evidence that tumor cells activate a compensatory glucose-lipid metabolic feedback loop mediated by SREBP-1, effectively blunting the impact of lysosomal inhibitors.

At the heart of the discovery is a complex signaling cascade wherein SREBP-1 not only enhances glucose uptake but also orchestrates lipid biosynthesis pathways that cooperate to sustain tumor growth. By increasing glucose flux into the cancer cells, SREBP-1 counterbalances the metabolic disruption caused by lysosomal inhibition, facilitating mitochondrial resilience, and reducing oxidative stress-induced apoptosis. This metabolic plasticity confers a survival advantage, rendering single-agent lysosomal inhibitors insufficient.

The researchers employed sophisticated preclinical models involving both cell cultures and animal subjects to unravel this mechanism. They demonstrated that combining lysosomal inhibitors with agents that simultaneously disrupt glucose transport can induce mitochondrial dysfunction, heighten oxidative stress, and trigger extensive tumor cell death. This dual targeting strategy effectively dismantles the metabolic safety net tumors rely on in the face of lysosomal suppression.

“Our findings reveal an unanticipated metabolic crosstalk and regulatory loop that tumors exploit to withstand lysosomal-targeted therapy,” explained Deliang Guo, PhD, founding director of the Center for Cancer Metabolism at OSUCCC – James and corresponding author of the study. “By intervening at multiple metabolic nodes, particularly glucose and lipid metabolism along with lysosomal activity, we can strategically dismantle tumor defenses and enhance therapeutic efficacy.”

This metabolic feedback loop is significant not just for lung cancers but potentially for a broad spectrum of malignancies characterized by elevated metabolic demands. Tumors with aggressive phenotypes often exhibit heightened uptake of glucose and lipids, which fuels their rapid growth and resistance to stress. Targeting the metabolic flexibility of tumors thus emerges as an innovative avenue to overcome resistance mechanisms that have stymied conventional therapies.

Yaogang Zhong, PhD, senior author and lead researcher on the project, emphasized the clinical relevance: “This approach holds particular promise for patients with lung squamous cell carcinoma and specific subsets of adenocarcinoma who lack actionable genetic mutations, leaving them with limited treatment options. The combinatorial therapeutic strategy we propose harnesses existing drugs with well-established safety profiles, expediting the bench-to-bedside transition.”

Indeed, both chloroquine and simvastatin — commonly used in clinical settings for malaria and cholesterol management respectively — are repurposed drugs that the study utilized. Furthermore, the fatty acid synthesis inhibitor TVB-2640, already in advanced phase II/III clinical trials, complements this triple-pronged assault on tumor metabolic machinery. The convergence of these agents into a cohesive treatment protocol highlights the translational potential of the findings.

Mechanistically, glucose transporter inhibition amplifies mitochondrial vulnerability by preventing the energy substrate influx required for survival during lysosomal stress. This mitochondrial damage precipitates oxidative stress, destabilizing tumor cell homeostasis and culminating in apoptosis. Simultaneously, lipid metabolism disruption interrupts membrane biogenesis and signaling lipid production essential for tumor viability, collapsing the compensatory metabolic loop.

This research not only deepens fundamental understanding of cancer metabolism but also advocates for integrated therapeutic regimens that consider the networked nature of tumor survival pathways. By exploiting the metabolic dependencies of tumors, combinations that target lysosomal pathways in concert with glucose and lipid metabolic circuits can yield robust antitumor responses.

As the metabolic landscape of cancer cells continues to be an ever-expanding frontier, these findings illuminate new targets and strategies to counteract the adaptability that makes tumors so formidable. The study thus marks a pivotal advance in precision oncology, setting the stage for clinical trials that could redefine treatment standards for patients with refractory lung cancers.

Future investigations are poised to explore the applicability of this metabolic combination approach to other cancer types exhibiting metabolic plasticity. Moreover, understanding the precise molecular interactions within the glucose-lipid-lysosome axis may uncover additional therapeutic targets and biomarkers predictive of treatment response.

In conclusion, this seminal study spearheaded at OSUCCC – James offers a compelling roadmap to outmaneuver NSCLC resistance by dismantling a metabolic feedback loop critical for tumor persistence. Through strategic combination therapies that are already clinically accessible, there is renewed hope to significantly improve outcomes for patients battling some of the most aggressive and treatment-resistant lung cancers.

Subject of Research: Tumor resistance mechanisms in non-small cell lung cancer; lysosomal inhibition and metabolic regulation.

Article Title: SREBP-1 increases glucose uptake to promote tumor resistance to lysosome inhibition

News Publication Date: 28-Jan-2026

Web References:
https://cancer.osu.edu
https://pubmed.ncbi.nlm.nih.gov/41604461/

Image Credits: The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute

Keywords: Non-small cell lung cancer, lysosomal inhibition, SREBP-1, glucose metabolism, lipid metabolism, tumor resistance, chloroquine, simvastatin, TVB-2640, metabolic therapy, cancer metabolism, therapeutic strategy

Pancreatic ductal adenocarcinoma (PDAC), the most prevalent and aggressive form of pancreatic cancer, poses unique obstacles for treatment due to its cellular composition and microenvironment. Intriguingly, PDAC tumors often consist predominantly of non-malignant cells, with cancerous cells comprising as little as ten percent in some tumors. This cellular heterogeneity complicates therapeutic targeting and contributes to treatment failure. Malignant cells within these tumors face significant metabolic stress because the tumor vasculature is dysfunctional, limiting nutrient delivery. Nevertheless, these cells adapt by activating alternative biochemical processes that sustain their survival and proliferation.

Central to these adaptive mechanisms are intracellular recycling pathways mediated by lysosomes—organelles traditionally known for degrading cellular waste. Researchers have long recognized that lysosomes facilitate cancer cell survival in nutrient-poor environments by recycling macromolecules and repurposing biomolecules essential for tumor growth. However, the precise molecular targets within lysosomes and their roles in PDAC remained poorly understood. The University of Michigan team focused on PIKfyve, an enzyme involved in phosphoinositide metabolism and lysosomal membrane dynamics, with prior evidence implicating it in other malignancies but unclear impact on pancreatic cancer.

Leveraging advanced genetic engineering techniques, the investigators created mouse models deficient in PIKfyve, observing a marked reduction in pancreatic tumor development compared to controls. Furthermore, pharmacological inhibition of PIKfyve using compounds apilimod and ESK981 led to significant suppression of tumor growth in these models over a ten-week treatment course. These compelling findings established that PIKfyve activity is crucial for maintaining lysosomal functions that, in turn, support PDAC progression.

To unravel the underlying molecular mechanisms, the researchers employed human pancreatic cancer cell lines treated with PIKfyve inhibitors to delineate gene expression changes. Their analyses revealed that PIKfyve suppresses the cellular demand to synthesize new fatty acids by facilitating lysosomal recycling of lipid components. When PIKfyve activity is blocked, malignant cells lose the ability to efficiently recycle fats and are forced to upregulate de novo lipid biosynthesis pathways to meet their metabolic needs. This metabolic rewiring underscores the interdependence between lysosomal function and oncogenic lipid metabolism in PDAC.

Intriguingly, the KRAS-MAPK signaling cascade—a critical oncogenic driver mutated in over 90 percent of pancreatic cancers—was identified as the pathway through which tumor cells ramp up fatty acid synthesis under PIKfyve inhibition. Given that KRAS is often considered the “master regulator” of pancreatic tumorigenesis, therapies aimed at inhibiting KRAS have garnered significant attention, some advancing into clinical trials. Nonetheless, resistance to KRAS inhibitors remains a prominent obstacle, highlighting the limitations of monotherapy in this aggressive cancer.

The University of Michigan study importantly demonstrated that dual inhibition of PIKfyve and KRAS-MAPK pathways results in profound anti-tumor effects. This combination therapy effectively eradicated pancreatic tumors in several sophisticated preclinical models, providing a strong rationale for therapeutic synergy. By simultaneously blocking lysosomal recycling and the compensatory lipid synthesis mechanism, cancer cells were deprived of essential nutrients to sustain growth, culminating in tumor regression and cure in these experimental systems.

This research serves as a compelling proof-of-concept for targeting cancer metabolism — in particular, lipid metabolism — in concert with oncogenic signaling pathways to overcome intrinsic metabolic plasticity. The findings indicate that inhibiting PIKfyve not only disrupts lysosome-driven nutrient recycling but also primes cancer cells to become more susceptible to KRAS inhibition by forcing a metabolic bottleneck. This dual-pronged approach represents a novel strategy to outmaneuver tumor adaptive mechanisms that have historically undermined treatment outcomes in pancreatic cancer.

Moreover, the study authors emphasize the eventual necessity of integrating immunotherapeutic strategies to fully extinguish residual disease. Malignant cells have evolved intricate backup pathways enabling survival despite extensive metabolic targeting. Therefore, harnessing the immune system to recognize and eradicate tumor cells that escape metabolic blockade could be the critical missing element in achieving durable cures. Ongoing research aims to identify immune recruitment modalities that cooperate with metabolic therapy for maximal effect.

In summary, this groundbreaking work delineates a new frontier in pancreatic cancer therapeutics by illuminating the vital role of PIKfyve in lysosome-mediated lipid metabolism and its interplay with KRAS-driven oncogenesis. The presented preclinical evidence heralds a promising era where combination therapies tailored to disrupt metabolic dependencies and oncogenic circuits may finally subvert this devastating disease. While challenges remain in translating these findings clinically, the study offers a beacon of hope that synergistic targeting of metabolic and signaling pathways can rewrite the therapeutic narrative for pancreatic cancer.

As the global oncology community continues to grapple with pancreatic cancer’s complexity, the identification of PIKfyve as a druggable target and the demonstrated efficacy of combining its inhibition with KRAS blockade mark a pivotal advance. This research not only enriches understanding of PDAC biology but also charts a strategic path forward towards more effective, durable therapies. Future clinical trials will be crucial to validate these preclinical successes and potentially transform standard-of-care paradigms, ultimately improving survival and quality of life for patients afflicted with this relentless malignancy.

Subject of Research: Animals

Article Title: Targeting PIKfyve-driven lipid metabolism in pancreatic cancer

News Publication Date: 23-Apr-2025

Web References:
https://www.nature.com/articles/s41586-025-08917-z
http://dx.doi.org/10.1038/s41586-025-08917-z

References:
University of Michigan, Department of Oncology et al. "Targeting PIKfyve-driven lipid metabolism in pancreatic cancer," Nature, 23 Apr 2025.

Keywords: Health and medicine; Pancreatic tumors; Molecular targets; Cancer research; Mouse models