Biology subjects

Patel, A.

Publications and source records attributed to Patel, A..

At least 19 recordsLinked to original sources

bioRxiv2026

Conserved patterns of mammal-microbe codiversification and interspecific bacterial sharing

What determines whether a gut microbial lineage has fidelity to one host species or is shared freely across multiple species? Factors that predict microbial community composition, including host species, diet, and environmental variation, have been well documented in wild animals. However, the eco-evolutionary processes maintaining host species- or population-specific microbial lineages remain unresolved. Here, we analyze 519 gut microbiome samples collected from 15 species of wild rodents across two mountains in the Madrean Sky Islands of southeastern Arizona using full-length 16S rRNA sequencing. This montane system provides a natural experiment in which adjacent replicated elevational gradients bring different combinations of rodent species into sympatry, allowing host evolutionary history to be disentangled from shared environmental effects. We find that host phylogeny, rather than environment, is the primary driver of microbial strain sharing across host species. We recover replicated signatures of codiversification on both mountains, indicating shared evolutionary history between hosts and their microbes, despite ample opportunities for cross-species environmental transmission. This evolutionary coupling is associated with predicted differences in bacterial oxygen tolerance and optimal growth temperature: codiversifying lineages are predominantly obligate anaerobes with optimal growth near host body temperature, suggesting more limited out-of-host persistence than non-codiversifying taxa. This pattern mirrors findings from the human gut microbiome, suggesting conserved constraints on microbial dispersal across mammalian hosts. The cost-effectiveness of long-read amplicon sequencing for phylogenetic inference within bacterial species opens new opportunities for large-scale evolutionary and ecological studies of host-microbe interactions in wildlife.

ecology↗

bioRxiv2026

Adaptive respiratory bypass restores oxidative metabolism in NADH dehydrogenase-deficient Escherichia coli

Nicotinamide adenine dinucleotide is central to the cellular redox network and continuously cycles between its oxidized (NAD) and reduced (NADH) forms. Membrane-bound NADH dehydrogenases are the primary NADH-oxidizing enzymes and principal entry point for reducing equivalents into the bacterial respiratory chain. While maintaining optimal balance of this redox cofactor is among the most fundamental biochemical constraints on living systems, how cells adapt when the primary NADH oxidation route is lost remains poorly understood. Here we show that Escherichia coli lacking both NADH dehydrogenases initially compensates through costly fermentative lactate secretion, potentially to maintain redox and energy homeostasis, but at the cost of impaired growth and oxidative metabolism. Using adaptive laboratory evolution across four independent lineages, we found that all evolved populations derepressed malate:quinone oxidoreductase by disrupting an ArcA-binding site. This gain-of-function mutation establishes an alternative pathway that funnels electrons directly into the quinone pool, restoring respiratory oxygen consumption to wild-type level. Multi-omics and genome-scale metabolic modeling reveal that this bypass drives broad reorganization of central carbon metabolism, reinstates tricarboxylic acid cycle flux, and shifts cells toward a higher, more oxidative aero-type. These findings uncover a previously unrecognized metabolic buffering capacity that enables bacteria to circumvent loss of canonical respiratory entry points.

microbiology↗

bioRxiv2026

CTL1 (SLC44A1) regulates myelin lipid composition and architecture in Schwann cells

Myelin formation requires extensive membrane lipid synthesis, yet how myelinating glia acquire the choline needed for this process remains incompletely understood. Choline transporter-like protein 1 (CTL1; SLC44A1) is highly expressed in Schwann cells, and CTL1 deficiency in oligodendrocytes impairs CNS myelination. Here, we examined the role of CTL1 in peripheral nerve myelination using Schwann cell-specific Ctl1 knockout mice. Unexpectedly, loss of Ctl1 did not alter Schwann cell differentiation, the number of myelinated axons, or myelin thickness, but increased myelin abnormalities, including in-foldings and out-foldings. Lipidomic analysis revealed selective alterations in myelin lipid composition, particularly among long-chain lipid species, together with triglyceride accumulation in whole nerves. CTL1 deficiency also increased mTORC1-associated S6 and mTORC2-associated AKT S473 phosphorylation. Transcriptomic analysis revealed downregulation of gene programs associated with fatty acid {beta}-oxidation, triglyceride catabolism, and oxidative phosphorylation. Following peripheral nerve injury, Ctl1-deficient Schwann cells generated a normal repair response and efficiently remyelinated regenerated axons despite altered mTOR signaling. Together, these findings demonstrate that CTL1 is not required for overall peripheral myelin production but contributes to maintaining normal myelin lipid composition and architecture, revealing an unexpected ability of Schwann cells to sustain myelination despite disruption of CTL1-dependent choline metabolism

neuroscience↗

bioRxiv2026

Spatial/molecular heterogeneity and treatment response in HER2+ early breast cancer: Translational analyses from the DAPHNe trial

Given the heterogeneity of HER2-positive breast cancer, reliable biomarkers to guide treatment are needed. We conducted multi-platform biomarker analyses of baseline tumor tissue from the DAPHNe trial of neoadjuvant paclitaxel/trastuzumab/pertuzumab (THP) for HER2-positive early breast cancer to characterize inter- and intra-tumor heterogeneity and to identify molecular predictors of response. A total of 98 patients with stage II-III HER2-positive breast cancer received neoadjuvant THP followed by surgery. Gene expression profiling, spatial protein profiling, and single-cell imaging (cyclic immunofluorescence) were performed on pre-treatment biopsies and a subset of residual disease specimens. Pathologic response was assessed using the residual cancer burden (RCB) score. Among HER2-positive patients included in the biomarker analysis, 34% of patients had node-positive breast cancer, and 66% had hormone receptor (HR)-positive tumors. HR-positive and HR-negative tumors differed significantly across gene expression, protein expression, and single-cell profiling. High ERBB2 gene signature, p53 gene signature, and HER2 protein expression predicted favorable response (RCB 0/1), while ESR1/PGR gene, estrogen receptor (ER) signaling gene signature, and ER alpha protein expression were associated with unfavorable response (RCB 2/3). Single-cell spatial analysis revealed that cancer cells clustered by shared HER2, ER, and PR expression, suggesting local expansion of phenotypically distinct subpopulations. ER-positive cancer cells were associated with lower HLA-A and PD-L1 expression, suggesting a less immunologically active tumor cell state. Baseline HER2 and ER expression are key predictors of response to neoadjuvant HER2-targeted therapy. Single-cell spatial profiling highlights intra-tumoral heterogeneity and suggests ER-driven immune exclusion as a potential mechanism of resistance.

cancer biology↗

bioRxiv2026

Distinct Spatial Immune Architectures in Tumor and Tumor-Adjacent Tissues of Early-Stage Non-Small Cell Lung Cancer

Background: Lung cancer remains the leading cause of cancer-related deaths in the United States with over 124,000 estimated deaths for 2026. Previous studies have found that tumor-adjacent lung tissues may provide additional insight into the immune microenvironment of early-stage NSCLC. Methods: Multiplex immunofluorescence (mIF) imaging was performed on 192 tissues from 101 early-stage non-small cell lung cancer patients including 91 matched tumor-adjacent pairs, using three mIF panels. Spatial analyses were performed to identify distinctions between tissues and identify associations with clinical and genomic features. Results: Tumor tissue showed significantly higher densities of T cells, macrophages, B cells, and memory/regulatory populations than adjacent tissue (p<0.001). Tumors exhibited greater spatial heterogeneity, with higher prevalence of spatial patterning (47.7% vs. 31.2%) and more consistently localized organization, whereas adjacent tissue showed stronger individual-cell clustering. Pairwise colocalization (Ripley's L-cross) revealed selective spatial segregation in tumors (including B-cells from memory/regulatory cells and among cytotoxic T-cell subsets) and reduced immune proximity to malignant cells relative to the strong immune-epithelial association in adjacent tissue. Spatial features were linked to genomic features or patient outcomes: tumor neoantigen burden exhibited a positive association with CD3+ T cells in the tumor, while colocalization between CD45RO+CD57+GZMB+ cells and CD57+GZMB+ cells was negatively associated with overall survival outside the tumor. Conclusion: Tumor and adjacent tissues harbor distinct spatial immune architectures, with spatial features displaying associations with genomic features or patient outcomes. These findings highlight immune microenvironment reorganization and the importance of incorporating spatial context from both compartments into risk assessment in NSCLC.

immunology↗

bioRxiv2026

Cheetahs Combine Head Pitch Stabilisation with Predictive Yaw Tracking during High-speed Pursuit

Predators pursuing agile prey must coordinate locomotion with rapidly changing visual information, yet how they control head orientation during high-speed terrestrial pursuit remains poorly understood. We reconstructed three-dimensional head, torso, and lure target trajectories from synchronised multi-camera recordings of freely running cheetahs (Acinonyx jubatus) using model-based markerless reconstruction, and propagated reconstruction uncertainty through Monte Carlo analysis. Across 1,373 valid reconstructed pursuit frames, head pitch was more closely aligned with the target than torso pitch, and is tightly stabilised relative to target elevation. Head-on-torso counter-rotation nearly cancelled concurrent torso-pitch rotations, preserving target-relative head pitch despite locomotor oscillations. In yaw, cheetahs predominantly oriented their heads ahead of the target's instantaneous position while maintaining a distinct locomotor heading and continuing to close range. During steady-lateral pursuit, head yaw was best described by a short horizon constant-velocity extrapolation model with a cross-validated median prediction horizon of 45 ms. Together, these findings reveal complementary head orientation strategies during pursuit: robust sagittal stabilisation and predictive lateral tracking keep the head target-referenced while the torso generates a closing trajectory towards intersection.

animal behavior and cognition↗

bioRxiv2026

Astrocytic chordin-like 1 (Chrdl1) is re-engaged early after ischemic stroke to regulate region-dependent GluA2 levels and neuronal vulnerability

Neuronal vulnerability to ischemic stroke varies markedly across brain regions, yet the mechanisms underlying this selective susceptibility remain poorly understood. Here, we show that the developmental astrocytic protein Chordin-like 1 (Chrdl1) is repurposed after ischemic injury to regulate neuronal vulnerability. Chrdl1 expression stabilizes GluA2-containing AMPA receptors, limits delayed apoptotic neuronal death, and preserves hippocampal function early after focal ischemic stroke, whereas sustained Chrdl1 expression does not improve long-term recovery. These findings identify an unexpected neuroprotective role for Chrdl1 during acute ischemia that contrasts with its previously described function as a limiter of synaptic plasticity during recovery. Our work reveals that developmental astrocyte-derived signaling can be redeployed after brain injury, with distinct functions depending on the stage of stroke and region-dependent endogenous expression that together determine whether a conserved neuroprotective mechanism is engaged after ischemic stroke.

neuroscience↗

bioRxiv2026

Semaglutide Activates the Orexin/Hypocretin and Basal Forebrain Cholinergic Systems and Increases Acetylcholine Levels in the Hippocampus of Young and Aged Rats

GLP-1 agonist drug repurposing efforts may establish new clinical niches in managing psychiatric and neurological disorders. However, a comprehensive understanding of GLP-1 neurobiology and an appreciation of specific neural mechanisms by which GLP-1 agonists might provide therapeutic effects is limited and stands as a barrier to these efforts. When considering current preclinical research evaluating GLP-1 agonist central mechanisms, a considerable knowledge gap remains regarding which specific cellular populations and systems define potential therapeutic effects in the brain. In this research, we used cFos immunohistochemistry to identify specific neuronal populations that exhibited altered cellular activity following acute administration of semaglutide to rats. We found that the orexin/hypocretin and basal forebrain cholinergic systems are activated following acute semaglutide administration in male and female young adult rats (3-5 months). Informed by the results of our histological analysis, we next employed in vivo microdialysis to test our hypothesis that semaglutide would acutely increase acetylcholine release in the rodent hippocampus. Here, we report that semaglutide acutely increases acetylcholine efflux in the ventral hippocampus of conscious and freely moving rats regardless of biological sex in both young adult and aged rats (23-26 months). Given the relevance of hippocampal cholinergic neurotransmission in learning and memory, our research mechanistically connects GLP-1 agonists with established targets in cognitive decline and dementia.

neuroscience↗

bioRxiv2026

On the Robustness of Biomolecular Systems to Perturbations in Translational Resources

The reliable operation of biomolecular circuits depends on the availability of shared cellular resources such as ribosomes, whose levels can vary substantially across growth conditions and cellular contexts. Although resource competition among co-expressed genes is well recognized, the relationship between resource variation and the robustness of circuit dynamics has not been characterized quantitatively. This paper integrates a resource-aware gene expression model, contraction theory-based analytical bounds, and experimental validation to study the effect of translational resource variation on constitutive gene expression and its mitigation through feedback. We show that the constitutive circuit exhibits sensitivity to resource perturbations, and that redesigning it with negative autoregulatory feedback enhances the contraction rate and reduces the steady-state deviation bound, though at lower expression levels. Experiments in E. coli using both plasmid copy number variation and a ribosome sequestration module are consistent with these predictions, confirming that the feedback circuit maintains relatively stable expression under conditions where the constitutive circuit shows large changes. These findings offer a systematic approach for analyzing and improving the robustness of biomolecular circuits operating under variable resource conditions.

systems biology↗

bioRxiv2026

HER2 mutation-derived neoantigens in NSCLC as actionable targets for TCR therapy

HER2 mutations are oncogenic drivers in 1-6% of non-small cell lung cancers (NSCLC), but therapeutic resistance limits the durability of current HER2-targeted treatments. Here, we identify T-cell receptors (TCRs) targeting recurrent HER2 hotspot mutations as a potential immunotherapeutic strategy for HER2-mutant NSCLC. Using neoepitope prediction and antigen-specific T-cell enrichment, we isolated HLA-A*02:01restricted TCRs recognizing HER2 A775insYVMA, S310F, and G776delinsVC mutations, collectively covering approximately 60% of HER2-mutant NSCLC. These TCRs selectively recognized mutant HER2 epitopes without detectable wild-type reactivity and some displayed cross-recognition of related hotspot variants, expanding the spectrum of targetable tumors. The G776delinsVC-specific TCR also exhibited co-receptorindependent activity showcased by its ability to activate CD4+ T cells. Importantly, timelapse single-cell flow cytometry analyses demonstrated that TCR-engineered T cells repeatedly reacquired activated polyfunctional states following serial antigen stimulation, while serial tumor rechallenge assays confirmed sustained cytotoxic activity across multiple rounds of tumor killing. These findings identify recurrent HER2 mutations as shared immunotherapeutic targets and provide a foundation for the development of TCR-based therapies for HER2-mutant NSCLC.

immunology↗

bioRxiv2026

Scaling of Noise Under Resource Constraints in Gene Regulatory Motifs

Understanding noise propagation in gene regulatory circuits requires accounting for both model and resource constraints. In this work, we investigated the role of model order in influencing stochastic behaviour by deriving and analytically comparing reduced protein-only models with higher-order models that include mRNA and molecular complexes, and found that protein-based models can exhibit higher noise levels in the gene expression. Through frequency-response analysis, we explained that the higher-order models provide additional noise-filtering effects. We also analyzed a one-dimensional constrained model and showed that the Fano factor decreases as the strength of resource constraint increases. Finally, we considered larger circuit motifs, such as toggle switches and incoherent feed-forward loops, and found that resource limitations can minimise stochastic switching in a bistable circuit, whereas in an incoherent feed-forward loop, resource constraints can make the adaptation faster. Our results highlight that both mechanistic detail and shared resource constraints play a central role in determining fluctuation levels in biomolecular circuits.

systems biology↗

bioRxiv2026

Deformable Models-Based Retinal OCT Layer Segmentation and Classification with Feature Analysis

Optical coherence tomography (OCT) is widely used for retinal disease assessment, but automated quantitative analysis remains challenging because of anatomical variability and noisy imaging conditions. This study presents an interpretable OCT classification framework based on four anatomically guided retinal layers, combining preprocessing, adaptive segmentation, targeted feature engineering, and supervised classification to identify Normal, CNV, DME, and Drusen cases. Layer-specific descriptors included statistical, derivative, fluid-related, and GLCM texture markers. Feature correlation and ranking analyses showed that the proposed descriptors were highly complementary, that the most informative features were concentrated in layers 2 and 4, and that layers 1 and 3 contributed supportive structural information. Among the evaluated classifiers, the neural network performed best, achieving an accuracy of 98.17%, sensitivity of 97.88%, specificity of 99.38%, and AUC of 0.9985. Computational analysis showed efficient training and inference, with a total training time of 2216.3 s, prediction speed of approximately 160000 observations per second, and a compact model size of about 11 kB. These results demonstrated that anatomically guided feature extraction can provide accurate, efficient, and interpretable OCT disease classification, offering a practical alternative to less transparent end-to-end deep learning approaches.

bioinformatics↗

bioRxiv2026

Integrated risk assessment reveals low biological activity of RNA-based crop protection formulations across plant and non-target systems

RNA-based crop protection products are considered promising alternatives to conventional pesticides due to their high target specificity and selectivity profile. While current risk assessments mainly focus on sequence-dependent off-target effects, potential sequence-independent effects of RNA molecules and formulation components remain poorly understood. Here, we assessed the potential of naked and formulated RNA molecules to induce unintended biological responses in plants and non-target organisms using complementary plant stress and cellular toxicity assays. Single-stranded RNA (ssRNA), double-stranded RNA (dsRNA), circular RNA (circRNA), and chitosan-based RNA formulations were evaluated for their ability to induce early stress responses in plants and adverse effects in insect cells. Cytosolic Ca{superscript 2} signaling and reactive oxygen species (ROS) production were monitored in barley and Arabidopsis, while impedance-based phenotypic profiling (ECIS) was used to assess cellular responses in Spodoptera frugiperda (Sf21) cells. Neither naked nor formulated RNA preparations triggered pronounced Ca{superscript 2} influxes or ROS bursts, indicating an absence of substantial activation of early plant defense signaling. Likewise, RNA formulations caused only minor effects on insect cell attachment and spreading as a measure for cell viability. Observable responses occurred primarily at elevated concentrations of RNA formulations and were formulation-dependent rather than RNA-dependent. Overall, the investigated RNA molecules exhibited low biological activity across the tested non-target systems. Our results highlight the importance of evaluating RNA active ingredients and delivery matrices separately and demonstrate the value of integrated screening approaches for the early hazard assessment of RNA-based crop protection products.

Plant Biology↗

bioRxiv2026

Sensorimotor dynamics of target acquisition and homing in human echolocation

Blindness imposes constraints on the acquisition of environmental sensory information. To mitigate those constraints, some blind people employ active echolocation, a technique in which self-generated tongue "clicks" produce informative reflections from surrounding surfaces. Practitioners typically produce multiple clicks that guide, and are in turn shaped by, goal-relevant action. What perceptual information is gained in the echoacoustic signal from each click, and how does it inform motor behavior during task performance? To explore these poorly understood dynamics, here we recorded head movements and clicking behavior of an early-blind expert echolocation practitioner who localized and oriented toward a target object positioned at a 1 m distance and random azimuth in the frontal hemifield. Three additional participants, including a blind self-reported echolocator, were unable to perform the task better than chance level. Performance clearly benefited from available echoacoustic information: The larger target was localized with an average absolute angular error of 9.5{degrees} in 9.3 s, vs. 24.6{degrees} in 23.2 s for the smaller target. In a passive control condition prohibiting clicks altogether, no significant convergence on the target was observed, confirming the necessity of active sampling. Clicks were emitted somewhat more rapidly and intensely for small targets, but within-trial emission rate and head kinematics (left-to-right reversals) remained relatively invariant. Angular convergence toward the target was consistent with an exponential decay profile, though only weakly distinguishable from a linear trend for small targets. Pooled across trials within each condition, clicks were unimodally distributed about the target azimuth, suggesting an intensity-maximization strategy. In sum, clicking behavior and target size (therefore sonar strength) strongly influenced the rate and precision of orientation convergence toward the target, suggesting that dynamic interactions between motor-driven head movements, click production, and the resulting echoacoustic feedback accumulate goal-relevant evidence across multiple samples. Together, these results illustrate naturalistic sensorimotor dependencies underlying auditory active sensing in the absence of vision.

neuroscience↗

bioRxiv2026

Dorsal striatal circuit mechanisms contributing to astrocyte modulation of alcohol-related behaviors

BackgroundThe dorsolateral striatum (DLS) is a key site for coordinating the alcohol-induced stimulant response, a behavioral marker predictive of future alcohol use disorder. Although ethanol (EtOH) affects all brain cells, little is known about the contribution of non-neuronal DLS cell types to EtOH-induced stimulation. MethodsWe used ex vivo two photon calcium imaging, in vivo fiber photometry of astrocyte and neuronal GCaMP, and astrocyte-specific manipulations in mice to determine DLS astrocyte contributions to EtOH-induced stimulation and voluntary EtOH drinking behavior. Using fiber photometry of GRAB-ACh sensors and cell-type specific chemogenetics, we also assessed the role of cholinergic signaling in observed astrocyte EtOH effects. ResultsAs expected, intraperitoneal EtOH injections (0.5-2g/kg) evoked a stimulant response, evidenced by increased locomotion compared to saline. In parallel, EtOH dose-dependently decreased astrocyte calcium activity but had minimal effects on direct and indirect pathway neuronal activity. Mimicking this reduction with astrocyte-specific expression of CalEX, a calcium extruding pump, facilitated EtOH stimulation compared to mice expressing a control fluorophore. Hence, EtOH-induced suppression of DLS astrocyte activity contributes to stimulation. Astrocyte calcium signaling is a well-known target of neuromodulation. Fiber photometry recordings of extracellular acetylcholine (ACh) levels via GRAB-ACh imaging showed inhibition of ACh release by acute EtOH. We virally expressed the excitatory chemogenetic actuator hM3Dq in striatal cholinergic interneurons to assess whether artificially increasing ACh release blocks EtOH-induced inhibition of astrocytic calcium activity. Despite facilitating ACh release, this manipulation did not impact astrocyte calcium activity under control (saline) or EtOH conditions. Together, this work identifies DLS astrocytes as key contributors to EtOH-induced stimulation and highlights the importance of considering astrocyte-neuron interactions in evaluating alcohol effects.

neuroscience↗

bioRxiv2026

Beyond distance-decay: The Mississippi River shapes gut microbiome communities in the Peromyscus maniculatus species complex

Biogeographic barriers are fundamental in shaping the distribution of animals and plants, yet the role of discrete landscape features in constraining microbial dispersal remains poorly understood. Identifying the barriers that partition gut microbial communities is essential for modeling the distribution of hosts and their symbionts across physical space and evolutionary time. The deer mouse (Peromyscus maniculatus species complex), which inhabits nearly all terrestrial environments in North America, provides an ideal model for testing these biogeographic drivers of the mammalian gut microbiome. Using NSF NEON biorepository samples, we characterized the gut microbiomes of 13 populations across the contiguous United States using full-length 16S rRNA long-read sequencing. While we observed a consistent distance-decay relationship across the continent, our results reveal that the Mississippi River acts as a major biogeographic break, significantly increasing microbial dissimilarity beyond the levels predicted by geographic distance alone. This "river effect" suggests that large fluvial systems impose a discrete barrier to microbial transmission, likely due to restricted host dispersal. Furthermore, we identified specific microbial lineages that exhibit differential sensitivity to this barrier, suggesting a gradient in microbial acquisition patterns ranging from the environment to host-host transmission. Together, these findings demonstrate that the gut microbiome may act as a sensitive bio-indicator of landscape-level ecological connectivity, revealing that large-scale landscape barriers disrupt microbial transmission even among closely related host populations that lack reproductive barriers.

microbiology↗

bioRxiv2026

Engineering Carbon Nanotube Quantum Well Defects with Recognition Tripeptides for Optical Detection of Extracellular Vesicles in Plasma

Extracellular vesicles (EVs) carry molecular signatures of their originating cells and have thus emerged as promising biomarkers. However, their clinical utility remains limited due to their low abundance and the modest sensitivity of current EV detection methods in complex biological environments. Here, we present a quantum well defect functionalized carbon nanotube sensor coupled with integrin-recognition RGD tripeptide for EV detection in human plasma. Leveraging the abundance of integrins on EV surfaces, we targeted 5{beta}1, V{beta}1, and V{beta}3 subtypes. The nanosensor exhibited robust hypsochromic shifts in defect emission upon integrin binding, achieving sub-picomolar detection limits for integrin subunits and quantifying EVs at concentrations as low as 104 EVs{middle dot}mL-1 for glioblastoma, ovarian cancer, and fibroblast cell-derived EV types. Molecular dynamics simulation indicated that integrin docking at the RGD-coupled quantum defect can substantially reshape the interfacial environments of the quantum defects, explaining the high sensitivity in EV detection in complex biological media. Finally, transmembrane protein analysis validated the expression of surface integrins across the tested EV types. The modular nanosensor construct can be targeted to detect disease-associated EV subpopulations, advancing EV-based diagnostics.

biochemistry↗

bioRxiv2026

Inhibition of miR-1307 Reverses Resistance to Cisplatin in Drug-Resistant Oral Squamous Cell Carcinoma

BackgroundChemo-resistance remains a major clinical challenge in Oral Squamous Cell Carcinoma (OSCC), attributed to the intrinsically resistant cells. Although tumour-derived extracellular vesicles (EVs) have been implicated in cell-cell communication, their role in propagating chemo-resistance remains poorly defined. This study aims to identify salivary EV-associated miRNAs capable of predicting chemoresistance and to delineate the role of miR-1307-5p in modulating CSC-driven therapeutic refractoriness. MethodsSalivary EV-derived expression profile of miR-1307-5p was assessed by qPCR in chemo resistant OSCC patients and further validated in TCGA small RNA sequencing datasets. Expression was validated by qPCR and correlated with clinicopathological outcomes. Functional assays including cell-cycle analysis, apoptosis, migration/invasion, 3D spheroids, angiogenesis, and CAM assays were performed in miR-1307-5p inhibited CD44 CSC subpopulation compared to its vehicular control. Transcriptomic profiling cross-referencing with TCGA was conducted to identify potential novel targets of miR-1307-5p. Chemo-sensitisation was assessed by treating the knockdown chemo resistant cells with low dose cisplatin and validating it using in-vitro functional assays and orthotopic xenograft model. ResultsmiR-1307-5p was significantly elevated in salivary EVs of chemo resistant OSCC patients and correlated with poor overall survival (p = 0.03). The miRNA was markedly enriched in endogenously resistant CD44 CSCs. Silencing of miR-1307-5p induced G2/M arrest, triggered apoptosis, impaired invasion, and reduced angiogenesis both in-vitro and in ex-vivo assays. Transcriptomic profiling, TCGA validation, and integrative pathway analysis identified key oncogenic hubs which converge on PI3K-AKT, MAPK/ERK, and YAP signalling pathways governing EMT. Inhibition of miR-1307-5p restored cisplatin sensitivity in resistant CSCs, with low-dose cisplatin producing substantial tumour suppression in-vitro and in-vivo. Reduced CD44 expression in xenograft models confirmed CSC reprogramming. EVs from anti-miR-treated cells confer chemo sensitisation upon uptake by resistant CSCs. Xenograft models substantiated that EVs can initiate tumour formation and that EV-mediated delivery of anti-miR-1307-5p drives significant tumour regression. ConclusionThis study identifies salivary EV-derived miR-1307-5p as a clinically relevant biomarker of chemoresistance in OSCC and reveals its mechanistic role in sustaining CSC-driven therapeutic failure. Targeting miR-1307-5p offers a promising avenue for restoring cisplatin sensitivity and developing exosome-based therapeutic strategies. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=150 SRC="FIGDIR/small/709730v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@19f88e0org.highwire.dtl.DTLVardef@d36b95org.highwire.dtl.DTLVardef@3c2579org.highwire.dtl.DTLVardef@c04ef5_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗