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bioRxiv2026

Systemic hypoxia drives glycogen-fueled progression of lung adenocarcinoma

In advanced stages, lung adenocarcinoma obstructs airways and disrupts ventilation-perfusion relationships in the lung, causing systemic hypoxemia and enabling a feed-forward loop that accelerates malignancy. Systemic hypoxemia is also experienced due to common respiratory comorbidities such as chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA), potentially accelerating malignancy. In a statewide electronic health record network, pre-existing COPD (598 matched pairs) or sleep apnea (235 matched pairs) independently predicted worse survival following incident lung cancer diagnosis. Since the mechanistic basis of the link between malignancy and hypoxia is not well understood, we created systemic hypoxia in KrasLSL-G12D/+;Trp53fl/fl (KP) mice by delivering low inspired oxygen concentrations (8% inspired oxygen; 8 h daily). Hypoxia nearly doubled tumor multiplicity and selectively remodeled cancer central carbon metabolism. Spatially resolved metabolomics revealed marked tumor-compartment glycogen accumulation, elevated tricarboxylic-acid cycle intermediates, and depleted glycolytic pools. Quantitative proteomics across cellular models and autochthonous tumors demonstrated that systemic hypoxia drives glycogen mobilization selectively through the lysosomal enzyme acid -glucosidase (GAA). Tumor-cell-autonomous deletion of GAA eliminated the hypoxia-driven growth advantage and disrupted downstream anabolic biosynthetic pathways. Thus, systemic hypoxia drives lung adenocarcinoma expansion by mobilizing lysosomal glycogen reserves through GAA to sustain proliferative growth.

cancer biology↗

bioRxiv2026

Complementary cytotoxicity of GD2-targeted photoimmunotherapy and 5-aminolevulinic acid photodynamic therapy in neuroblastoma and osteosarcoma

Phototherapy, a light-activated anticancer treatment, enables localized tumor-cell killing with distinct mechanisms of action. Photoimmunotherapy (PIT) produces immunogenic tumor cell death upon near-infrared light activation of a photoabsorber through antigen-specific targeting. Photodynamic therapy (PDT) produces reactive oxygen species through red-light activation of intracellular protoporphyrin IX generated from 5-aminolevulinic acid uptake and metabolism. PIT may have limited activity in antigen-low cells, whereas PDT has less precise tumor selectivity. We combined these modalities to define their interaction, broaden cytotoxicity, and determine whether dual treatment could reduce light-dose requirements. We conjugated dinutuximab, which targets the GD2 antigen, to IRDye 700DX and characterized plasma-membrane localization by confocal and widefield microscopy. PIT and PDT monotherapies were evaluated across agent and light doses in neuroblastoma (NB) and osteosarcoma (OS) cell lines. Combination matrices were tested using interaction, highest-single-agent, and Bliss analyses. Both monotherapies demonstrated significant light-dose-dependent effects in NB and OS. PIT produced no measurable cytotoxicity in antigen-blunted control cells, whereas PDT remained effective, confirming antigen-dependence of PIT and antigen-independence of PDT. The combination interaction was significant in SK-N-BE(2) but not LM7. At selected combinations, however, dual treatment produced greater killing than the more effective matched monotherapy in both SK-N-BE(2) and LM7 (Padj<0.022). Notably, lowest combination of PIT 10 J/cm2 plus PDT 10 J/cm2 achieved 90.3% killing in SK-N-BE(2), exceeding higher light-dose PIT or PDT monotherapy, suggesting a light-dose sparing effect. These findings establish potent and complementary PIT-PDT activity, supporting dual phototherapy to broaden cytotoxicity and reduce light-dose requirements in GD2-expressing tumor phototherapy.

cancer biology↗

bioRxiv2026

Microbial valerate is associated with CAR T dysbiosis and its supplementation enhances CAR T function in B-cell lymphoma

Anaerobe-depleting antibiotic exposure is associated with inferior progression-free survival after CD19 CAR T-cell therapy in large B-cell lymphoma, yet the cellular mechanisms linking gut dysbiosis to the CAR T-cell product and whether this imprint is reversible have remained undefined. In two independent CAR-T candidate cohorts, low stool valerate at the time of CAR-T eligibility identified a multi-metabolite-deficient dysbiotic gut microbiome state marked by depletion of fiber-fermenting commensals and loss of carbohydrate-fermentation, SCFA-biosynthesis, and amino-acid metabolism pathways. Reanalysis of single-cell RNA sequencing from 42 lymphoma patients stratified by piperacillin-tazobactam/imipenem/meropenem (PIM) exposure revealed that PIM-exposed CAR T-cell products were CD4-skewed, with significantly elevated AP-1/immediate-early gene (IEG) and cellular activation signatures that together predicted inferior progression-free survival. Ex vivo conditioning of CAR T-cells with valerate produced a chromatin and transcription factor program distinct from butyrate or propionate, characterized by KLF/SP/EGR family engagement, KLF4 promoter opening, and broad induction of AP-1/IEG and MHC class II transcripts, whereas butyrate drove broader chromatin remodeling with TBX21/EOMES/NF-{kappa}B gains and KLF2 promoter closure, and propionate induced an NFY-centered program with preferential commitment to low-mitochondrial-content states. Untargeted metabolomics confirmed valerate uptake and mitochondrial {beta}-oxidation in CAR T-cells, while dietary sodium valerate supplementation in meropenem-treated mice bearing A20 lymphoma significantly reduced tumor burden and extended survival compared with CAR T-cells alone. These findings identify stool valerate as a bedside-deployable biomarker of dysbiosis-imprinted CAR T-cell dysfunction and support ex vivo or dietary valerate supplementation as a clinically tractable strategy to improve CAR-T anti-tumor function in patients with disrupted gut microbiomes.

cancer biology↗

bioRxiv2026

Attenuated Salmonella-Mediated Delivery of GSDMD Potentiates PD-1 Blockade Therapy against Melanoma

Immunotherapy has emerged as a core therapeutic strategy for melanoma. Programmed death protein 1 (PD-1) is a critical immune checkpoint molecule that restrains host anti-tumor immunity, and therapeutic agents blocking the PD-1 signaling pathway have been widely deployed in clinical practice. Nevertheless, single-agent PD-1 blockade fails to elicit robust clinical responses in the majority of patients. Therefore, there is an urgent unmet need to develop combinatorial regimens capable of augmenting the anti-tumor efficacy of PD-1 inhibition. Gasdermin D (GSDMD), a pore-forming effector protein that orchestrates pyroptosis, exerts inherent anti-tumor activities upon overexpression. However, whether GSDMD can synergize with PD-1 blockade to enhance therapeutic outcomes against melanoma remains poorly defined. To address this question, we established an attenuated Salmonella engineered strain for targeted delivery of GSDMD, and further investigated the anti-melanoma therapeutic efficacy of combining this engineered bacterium with anti-PD-1 antibody via immunofluorescence staining, flow cytometry and other analytical approaches. Our in vivo results demonstrated that combinatorial treatment markedly suppressed melanoma progression in tumor-bearing mice relative to monotherapy with either GSDMD-expressing bacteria or anti-PD-1 antibody alone. Mechanistically, co-treatment upregulated intratumoral expression of GSDMD and the pro-apoptotic protein BAX, while simultaneously downregulating PD-1 expression. In addition, the GSDMD/anti-PD-1 combination significantly elevated the proportions of CD4 and CD8 T lymphocytes in both peripheral blood and splenic tissues, and facilitated robust tumor infiltration by these two T cell subsets. Compared with phosphate-buffered saline (PBS) and scramble control groups, combinatorial therapy promoted tumor infiltration of M1-type tumor-associated macrophages (TAMs) and repolarized TAMs away from the immunosuppressive M2 phenotype. Consistently, serum levels of the pro-inflammatory cytokines TNF- and IFN-{gamma} were markedly elevated following combined intervention. Collectively, this study verifies that attenuated Salmonella carrying GSDMD synergizes with anti-PD-1 antibody to elicit potent anti-tumor effects in melanoma-bearing mice by amplifying systemic and intratumoral anti-tumor immune responses, which provides a preclinical rationale for novel combinatorial therapeutic strategies against melanoma.

cancer biology↗

bioRxiv2026

Profiling Siglec-7 and Siglec-9 ligands across the LuCaP PDX series: Implications for glyco-immune checkpoint inhibition in advanced prostate cancer

Advanced prostate cancer exhibits profound cellular and molecular heterogeneity, frequently becoming resistant to androgen receptor (AR) targeting through lineage plasticity and neuroendocrine differentiation. Immunotherapies have shown limited efficacy in prostate cancer, largely due to its immunosuppressive tumour microenvironment. Hypersialylation contributes to immune evasion by engaging sialic acid-binding immunoglobulin-like lectins (Siglecs) on immune cells, forming glyco-immune checkpoints. Although this pathway represents a promising therapeutic target, the distribution of Siglec ligands across diverse prostate cancer phenotypes and their response to standard-of-care hormone therapy remain poorly understood. Here, we utilised high-affinity engineered sialoglycan-binding reagents (HYDRA) to perform comprehensive immunohistochemical profiling of Siglec-7 and Siglec-9 ligands across a panel of 40 Washington Carcinoma of the Prostate (LuCaP) patient-derived xenograft (PDX) models. Ligand expression was evaluated in relation to AR status and neuroendocrine phenotype. To determine the impact of androgen deprivation on the tumour glycome, ligand expression was compared between matched PDX lines grown in intact and castrated mice. Our findings reveal widespread but heterogeneous expression of Siglec-7 and Siglec-9 ligands across the LuCaP cohort. Expression levels were comparable between AR-positive adenocarcinoma models and AR-negative neuroendocrine variants, demonstrating that this glyco-immune checkpoint is maintained across distinct prostate cancer lineages. Under castration conditions, glycan remodelling occurred in a model-dependent manner. A subset of PDX models exhibited reduced Siglec ligand expression following castration, suggesting partial AR dependence. In contrast, other models displayed increased ligand expression, consistent with adaptive immune evasion in response to therapeutic stress, while a third group remained largely unchanged. Collectively, our study demonstrates that the Siglec-7/9 glyco-immune checkpoint axis is broadly maintained across the spectrum of prostate cancer lineage plasticity but is dynamically remodelled by androgen deprivation in a patient-specific manner. These findings support the sialoglycan-Siglec axis as a lineage-independent immunotherapeutic target and suggest that strategies aimed at disrupting Siglec-mediated immune suppression, such as tumour desialylation, may be most effective when combined with androgen deprivation therapy to enhance anti-tumour immunity.

cancer biology↗

bioRxiv2026

Membrane voltage and connexin expression work together to enhance tumor growth and metastasis in cancer

There is strong evidence of tumors manipulating their resting membrane potential (Vmem). While most fully-differentiated cells have a Vmem of roughly -70mV, tumor cells are generally depolarized, with Vmem {approx}-30mV, which more closely resembles the Vmem of stem cells. This is often believed to serve the purpose of accelerating the cell cycle and hence advantaging tumor proliferation. But when the tumor becomes invasive, its cells sometimes revert to a hyperpolarized Vmem with no obvious reason why. Separately, it is well accepted that solid tumors that are not yet invasive greatly underexpress connexins relative to healthy tissue; connexins, for our purpose, form gap junctions (GJs), small connecting tubes between nearby cells. Tumors that are invasive, by contrast, overexpress connexins. There is very little explanation for the paradox that connexins are first underexpressed and then overexpressed. However, it has long been known that Vmem electrically gates GJs; specifically, that homotypic GJs conduct best when the two cells they connect have a similar Vmem. Our in-silico model results explain this phenomenon, showing that when considered together, tumors' electrical and connexin-expression behaviors form a unified and effective strategy to control communication between the tumor and its healthy neighbor cells. This has implications for the emerging field of cancer bioelectrics, potentially leading to more precisely-targeted therapies.

cancer biology↗

bioRxiv2026

Vitamin D counters bone invasion by mammary cancer through inhibition of inflammation and epithelial-to-mesenchymal transition

Vitamin D deficiency is associated with poor outcome in several cancers in humans, and administration of vitamin D or analogs has been shown to decrease tumor progression and metastasis in animal mammary cancer models. We previously demonstrated significant acceleration of carcinogenesis in vitamin D-deficient mouse mammary tumor virus-polyoma middle T (MMTV-PyMT) mammary cancer model as well as of its spontaneous metastasis to lungs. While vitamin D also plays a role in skeletal metastasis, detailed mechanisms of its promotion of bone invasion and metastatic events are not completely elucidated. In the present study we used tibially-injected MMTV-PyMT mammary tumor cells to analyse how dietary-induced vitamin D deficiency in non-immunodeficient FVB mice accelerates bone invasion. Mechanistically, we observed vitamin D deficiency to increase pro-inflammation cytokines and nestin expression in internal bone surface and marrow, and to increase epithelial-to-mesenchymal transition (EMT) through Zeb1 transcription factor. In vitro, treatment of MMTV-PyMT tumor cells with CXCL12 was observed to stimulate Zeb1 expression, and this effect was efficiently countered by 1,25(OH)2D treatment. Analysis of cytokines in MMTV-PyMT mammary tumor cells in vitro showed significant reduction in several pro-inflammatory cytokines with 1,25(OH)2D treatment (GM-CSF, ICAM-1, IL-1ra, IP-10, JE, MCP-5, MIP-1, MIP-1{beta}, MIP-2, RANTES and CXCL12), a crucial observation in view of the current evidence that inflammation is one of the hallmarks of cancer. Furthermore, vitamin D repleteness is associated with very high expression of Socs1 (suppressor of cytokine signalling 1), an inhibitor of JAK/STAT pathway which prevents excessive inflammatory responses and has a tumor-suppressive role. These findings provide a strong link between vitamin D deficiency and acceleration of inflammation-driven bone invasion, and nestin and EMT. The evidence suggests that vitamin D-repleteness in breast cancer patients could enhance the efficacy of co-administered therapies in preventing invasion of skeletal sites.

cancer biology↗

bioRxiv2026

Nuclear Cathepsin L Remodels the Replication Machinery to Create a Therapeutic Vulnerability in Ovarian Cancer

Abstract Therapeutic resistance in ovarian cancer is frequently driven by persistent replication stress, yet the molecular mechanisms that convert replication stress into a therapeutically exploitable vulnerability remain incompletely understood. Here, we identify drug-induced nuclear cathepsin L (nCTSL) as a previously unrecognized regulator of replication stress and DNA repair. Clofarabine (CLF) combined with the ATR inhibitor AZD6738, or the CHK1 inhibitor prexasertib promoted nuclear accumulation of CTSL, where it remodeled the replication machinery through degradation of CCNE1, MCM3, MCM6, and geminin, accompanied by loss of RAD51 and 53BP1 and increased {gamma}H2AX and phospho-RPA2. DNA fiber analysis demonstrated marked inhibition of replication fork progression following CLF-based combinations, whereas CTSL depletion accelerated fork progression and abolished therapy-induced replication stress. Reconstitution with the nuclear M1F CTSL isoform restored replication restraint, confirming a direct role for nuclear CTSL in regulating replication dynamics. GFP-based DNA repair reporter assays further revealed that CLF-based combinations suppress DNA repair competence in a CTSL-dependent manner, indicating that nuclear CTSL couples replication stress amplification with functional inhibition of repair pathways. Functionally, CLF-based combinations selectively targeted transformed fallopian tube secretory epithelial cells while sparing non-transformed counterparts, demonstrated broad activity in patient-derived ovarian cancer ascites spheroids, and significantly inhibited tumor growth and prolonged survival in vivo. Collectively, our findings identify nuclear CTSL as a mechanistic driver of replication stress that remodels the replication machinery, impairs DNA repair, and creates a therapeutically exploitable vulnerability in ovarian cancer. We propose that nuclear CTSL promotes a transition from replication competence to replication catastrophe, thereby establishing a conceptual framework for biomarker-guided therapeutic strategies targeting CTSL-dependent replication stress.

cancer biology↗

bioRxiv2026

Integrative single cell analysis of CD8+ T-cells across early and advanced oral cancers reveals signatures of anti-tumour activity

Tumour-targeting CD8 T cells drive responses to every major form of cancer immunotherapy. Identifying them, however, remains an unsolved problem in solid tumours. The antigens they recognize are rarely defined and almost never shared between patients. We profiled 51,459 CD8+ T cells by paired single-cell RNA and T-cell receptor sequencing across 28 samples from 17 HPV-negative oral cancers spanning primary tumours, draining lymph nodes, metastases, and pembrolizumab-treated recurrences. We found that clonotypes that were expanded and shared across anatomical sites and timepoints were enriched within tumours and progressively selected over disease evolution and checkpoint blockade. Designating these shared-expanded clones as putative tumour-targeting cells, we trained a machine learning classifier that identifies them from transcriptome data alone. This 108-feature random forest signature recapitulated programmes of tumour reactivity and generalized to an integrated atlas of 89,318 CD8+ T cells from independent cohorts, showing progressive enrichment from normal to malignant tissue, and localized to tumour-proximal niches in spatial transcriptomics. By demonstrating that clonal behaviour across space and time encodes tumour reactivity in the transcriptome, this work establishes a generalizable framework for mapping tumour-engaged immunity without knowledge of the underlying antigen.

cancer biology↗

bioRxiv2026

Synergistic targeting of EP300/CBP and EYA co-activators collapses the rhabdomyosarcoma core regulatory circuit

Rhabdomyosarcoma (RMS) is a multi-subtype, high-risk pediatric sarcoma with a low mutational burden. The mutations found in RMS often alter genes involved in transcriptional control. Approaches to target dysregulated RMS transcription have remained elusive. Here, we develop a novel approach to target RMS transcription comprising simultaneous targeting of two distinctly acting transcriptional co-activators. We discover a common identity-controlling pan-RMS core regulatory circuit (CRC) composed of oncogenic and lineage-specific myogenic master transcription factors (mTFs). Using a super-enhancer-based reporter screen, we identify the EP300/CBP inhibitor A485 as a potent inhibitor of the pan-RMS CRC, though with efficacy-limiting toxicities. To enhance efficacy, we identify the mTF-binding co-activator EYA2 as a co-factor of this pan-RMS CRC and exploit a new second-generation EYA1/2 inhibitor, LG1-34, to disrupt its function. Combined co-activator inhibition inactivates the CRC and synergistically reduces RMS growth. This strategy dually targets CRC-associated co-activators to cooperatively suppress the RMS transcriptome and enforce cell death.

cancer biology↗

bioRxiv2018

Joint single cell DNA-Seq and RNA-Seq of gastric cancer reveals subclonal signatures of genomic instability and gene expression

Sequencing the genomes of individual cancer cells provides the highest resolution of intratumoral heterogeneity. To enable high throughput single cell DNA-Seq across thousands of individual cells per sample, we developed a droplet-based, automated partitioning technology for whole genome sequencing. We applied this approach on a set of gastric cancer cell lines and a primary gastric tumor. In parallel, we conducted a separate single cell RNA-Seq analysis on these same cancers and used copy number to compare results. This joint study, covering thousands of single cell genomes and transcriptomes, revealed extensive cellular diversity based on distinct copy number changes, numerous subclonal populations and in the case of the primary tumor, subclonal gene expression signatures. We found genomic evidence of positive selection - where the percentage of replicating cells per clone is higher than expected - indicating ongoing tumor evolution. Our study demonstrates that joining single cell genomic DNA and transcriptomic features provides novel insights into cancer heterogeneity and biology. SIGNIFICANCEWe conducted a massively parallel DNA sequencing analysis on a set of gastric cancer cell lines and a primary gastric tumor in combination with a joint single cell RNA-Seq analysis. This joint study, covering thousands of single cell genomes and transcriptomes, revealed extensive cellular diversity based on distinct copy number changes, numerous subclonal populations and in the case of the primary tumor, subclonal gene expression signatures. We found genomic evidence of positive selection where the percentage of replicating cells per clone is higher than expected indicating ongoing tumor evolution. Our study demonstrates that combining single cell genomic DNA and transcriptomic features provides novel insights into cancer heterogeneity and biology.

genomics↗

bioRxiv2017

LncRNA-TUG1/EZH2 Axis Promotes Cell Proliferation, Migration And The EMT Phenotype Formation Through Sponging miR-382

Pancreatic carcinoma (PC) is the one of the most common and malignant cancer in the world. Despite many effort have been made in recent years, the survival rate of PC still remains unsatisfied. Therefore, investigating the mechanisms underlying the progression of PC might facilitate the development of novel treatments that improve patient prognosis. LncRNA Taurine Up-regulated Gene 1 (TUG1) was initially identified as a transcript up - regulated by taurine, siRNA - based depletion of TUG1 suppresses mouse retinal development, and the abnormal expression of TUG1 has been reported in many cancers. However, the biological role and molecular mechanism of TUG1 in pancreatic carcinoma (PC) still needs to be further investigated. In the current study, the expression of TUG1 in the PC cell lines and tissues was measured by quantitative real-time PCR (qRT-PCR), and loss-of-function and gain-of-function approaches were applied to investigate the function of TUG1 in PC cell. Online database analysis tools showed that miR-382 could interact with TUG1 and we found an inverse correlation between TUG1 and miR-382 in PC specimens. Moreover, dual luciferase reporter assay, RNA-binding protein immunoprecipitation (RIP) and applied biotin-avidin pulldown system further provide evidence that TUG1 directly targeted miR-382 by binding with microRNA binding site harboring in the TUG1 sequence. Furthermore, gene expression array analysis using clinical samples and RT-qPCR proposed that EZH2 was a target of miR-382 in PC. Collectively, these findings revealed that TUG1 functions as an oncogenic lncRNA that promotes tumor progression at least partially through function as an endogenous sponge by competing for miR-382 binding to regulate the miRNA target EZH2.

cancer biology↗

bioRxiv2015

A comparative analysis of network mutation burdens across 21 tumor types augments discovery from cancer genomes

Heterogeneity across cancer makes it difficult to find driver genes with intermediate (2-20%) and low frequency (<2%) mutations1, and we are potentially missing entire classes of networks (or pathways) of biological and therapeutic value. Here, we quantify the extent to which cancer genes across 21 tumor types have an increased burden of mutations in their immediate gene network derived from functional genomics data. We formalize a classifier that accurately calculates the significance level of a genes network mutation burden (NMB) and show it can accurately predict known cancer genes and recently proposed driver genes in the majority of tested tumours. Our approach predicts 62 putative cancer genes, including 35 with clear connection to cancer and 27 genes, which point to new cancer biology. NMB identifies proportionally more (4x) low-frequency mutated genes as putative cancer genes than gene-based tests, and provides molecular clues in patients without established driver mutations. Our quantitative and comparative analysis of pan-cancer networks across 21 tumour types gives new insights into the biological and genetic architecture of cancers and enables additional discovery from existing cancer genomes. The framework we present here should become increasingly useful with more sequencing data in the future.

Cancer Biology↗

bioRxiv2018

TGF-βRII knock-down promotes tumor growth and chemoresistance to gemcitabine of pancreatic cancer cells via phosphorylation of STAT3

Pancreatic adenocarcinoma (PDAC) is one of the most deadly cancers in the western countries because of a lack of early diagnostic markers and efficient therapeutics. At the time of diagnosis, more than 80% of patients have metastasis or locally advanced cancer and are therefore not eligible for surgical resection. Pancreatic cancer cell also harbour a high resistance to chemotherapeutic drugs such as gemcitabine that is one of the main palliative treatment for PDAC.\n\nTGF-{beta} possesses both tumor-suppressive and oncogenic activities in pancreatic cancer. TGF-{beta} signalling pathway plays complex role during carcinogenesis by initially inhibiting epithelial growth and later promoting the progression of advanced tumors and thus emerged as tumor suppressor pathway. TGF-{beta} binds to its receptor TGF-{beta}RII and activates different pathways: canonical pathway involving the Smad proteins and alternative pathways such as MAPKs. Smad4 is mutated in 50-80% of PDAC. Mutations of TGF-{beta}RII also occurs (5-10%). In order to decipher the role of TGF-{beta} in carcinogenesis and chemoresistance, we decided to characterize the knocking down of TGF-{beta}RII that is the first actor of TGF-{beta} signalling. We developed pancreatic cancer cell lines stably invalidated for TGF-{beta}RII and studied the impact on biological properties of pancreatic cancer cells both in vitro and in vivo. We show that TGF-{beta}RII silencing alters tumor growth and migration as well as resistance to. TGF-{beta}RII silencing also leads to S727 STAT3 and S-63 c-Jun phosphorylation, decrease of MRP3 and increase of MRP4 ABC transporter expression and induction of a partial EMT phenotype.\n\nIn the future, the better understanding TGF-{beta} signaling pathways and underlying cellular mechanisms in chemoresistance to gemcitabine may bring new therapeutic tools to clinicians.

cancer biology↗

bioRxiv2018

Protein-Protein Interaction Network Analysis and Identification of Key Players in N-hydroxy-nor-L-Arg (nor-NOHA) and N(omega)-hydroxy-L-arginine (NOHA) Mediated Pathways for Treatment of Cancer Through Arginase Inhibiton: Insights from Systems Biology

L-arginine is involved in a number of biological processes in our bodies. Metabolism of L-arginine by the enzyme arginase has been found to be associated with cancer cell proliferation. Arginase inhibition has been proposed as a potential therapeutic means to inhibit this process. N-hydroxy-nor-L-Arg (nor-NOHA) and N (omega)-hydroxy-L-arginine (NOHA) has shown promise in inhibiting cancer progression through arginase inhibition. In this study, nor-NOHA and NOHA-associated genes and proteins were analyzed with several Bioinformatics and Systems Biology tools to identify the associated pathways and the key players involved so that a more comprehensive view of the molecular mechanisms including the regulatory mechanisms can be achieved and more potential targets for treatment of cancer can be discovered. Based on the analyses carried out, 3 significant modules have been identified from the PPI network. Five pathways/processes have been found to be significantly associated with nor-NOHA and NOHA associated genes. Out of the 1996 proteins in the PPI network, 4 have been identified as hub proteins-SOD, SOD1, AMD1, and NOS2. These 4 proteins have been implicated in cancer by other studies. Thus, this study provided further validation into the claim of these 4 proteins being potential targets for cancer treatment.

systems biology↗

bioRxiv2018

Somatic Mutations Render Human Exome and Pathogen DNA more Similar

Immunotherapy has recently shown important clinical successes in a substantial number of oncology indications. Additionally, the tumor somatic mutation load has been shown to associate with response to these therapeutic agents, and specific mutational signatures are hypothesized to improve this association, including signatures related to pathogen insults. We sought to study in silico the validity of these observations and addressed three questions. First, we investigated whether somatic mutations typically involved in cancer may increase, in a statistically meaningful manner, the similarity between common pathogens and the human exome. Our study shows that specific common mutagenic processes like those resulting from exposure to ultraviolet light (in melanoma) or smoking (in lung cancer) induce, in the upper range of biologically plausible frequencies, peptides in the cancer exome that are statistically more similar to pathogen peptides than the normal exome. Second, we investigated whether this increased similarity is due to the specificities of the mutagenic process or uniformly random mutations at equal rate would trigger the same effect. For certain pathogens the increased similarity is more pronounced for specific mutagenic processes than for uniformly random mutations and for other pathogens the effects cannot be distinguished. Finally, we investigated whether specific mutational processes result in amino-acid changes with functional relevance that are more likely to be immunogenic. We showed that functional tolerance to mutagenic processes across species generally suggests more resilience to natural processes than to denovo mutagenesis. These results support the idea that recognition of pathogen sequences as well as differential functional tolerance to mutagenic processes may play an important role in the immune recognition process involved in tumor infiltration by lymphocytes.

cancer biology↗

bioRxiv2016

Physical models of spatial genome organization

Remodeling of nuclear organization occurs during normal cell development, differentiation and cancer. One of the biggest gaps of knowledge remains how to link the information on chromatin and chromosome structural organization with genes activity. In this paper we introduce some physical ideas and a general computational method demonstrating how genome 3D architecture and its remodeling can be quantitatively modeled. We study a hypothetical scenario of alterations of chromosome territories positioning in the course of cell proliferation. On this basis we obtain quantitative information about chromosomal contacts in the nucleus. We predict changes of radial distributions of contacts between chromosomal megabase domains during proliferation. The proposed modeling approach may be helpful in integrating experimental data on nuclear reorganization associated with normal development and with various diseases. This predictive modeling may find applications in genome research of normal and cancer cells, stem cell biology, biology of aging, etc.

cancer biology↗

bioRxiv2018

Systematic Discovery of the Functional Impact of Somatic Genome Alterations in Individual Tumors through Tumor-specific Causal Inference

We report a tumor-specific causal inference (TCI) framework, which discovers causative somatic genome alterations (SGAs) through inferring causal relationships between SGAs and molecular phenotypes (e.g., transcriptomic, proteomic, or metabolomic changes) within an individual tumor. We applied the TCI algorithm to tumors from The Cancer Genome Atlas (TCGA) and identified those SGAs that causally regulate the differentially expressed genes (DEGs) within each tumor. Overall, TCI identified 634 SGAs that cause cancer-related DEGs in a significant number of tumors, including most of the previously known drivers and many novel candidate cancer drivers. The inferred causal relationships are statistically robust and biologically sensible, and multiple lines of experimental evidence support the predicted functional impact of both well-known and novel candidate drivers. By identifying major candidate drivers and revealing their functional impact in a tumor, TCI shed light on disease mechanisms of each tumor, providing useful information for advancing cancer biology and precision oncology.\n\nSignificance statementsCancer is mainly caused by SGAs. Precision oncology involves identifying and targeting tumor-specific aberrations resulting from causative SGAs. TCI is a novel computational framework for discovering the causative SGAs and their impact on oncogenic processes, thus revealing tumor-specific disease mechanisms. This information can be used to guide precision oncology.

cancer biology↗