Search bioRxiv⌕ Search

Biology subjects

Blandino, G.

Publications and source records attributed to Blandino, G..

8 recordsLinked to original sources

Pan-cancer analysis reveals genomic fidelity and evolution of patient-derived organoids

BackgroundPatient-derived organoids (PDOs) are gaining recognition as a promising ex vivo model for cancer research, offering advantages over traditional 2D cell lines by better recapitulating tumor biology. ResultsIn this study, we assess the genomic stability and evolution of PDOs by analyzing copy-number alterations (CNAs) in 300 PDO samples across 16 cancer types. These results are compared with data from previously analyzed patient-derived xenografts (PDXs). We observe that PDOs exhibit genomic evolution over passaging, with an increasing divergence from the original tumor genome over time. Importantly, across cancer types, PDOs maintain higher genomic fidelity and are more genetically similar to their tumors of origin than PDX models. Moreover, PDOs show greater genomic stability during culture passaging compared to PDXs. ConclusionsThese findings position PDOs as a reliable and representative model for cancer research, while highlighting the need to carefully track their genomic evolution in culture.

cancer biology↗

Inducible re-epithelialization of cancer cells increases autophagy and DNA damage: implications for breast cancer dormancy

Epithelial lineage differentiation is pivotal to mammary gland development and it can pause metastasis of breast cancer (BC) by inducing tumor dormancy. To simulate this, we expressed epithelial genes in mesenchymal BC cells. Inducible expression of the epithelial OVOL genes in metastatic BC cells suppressed proliferation and migration. We found that C1ORF116, an OVOLs target, is susceptible to genetic and epigenetic aberrations in BC. It is regulated by steroids and functions as a putative autophagy receptor that inhibits antioxidants like thioredoxin. Accordingly, boosting epithelialization lowered glutathione, elevated reactive oxygen species and increased both DNA oxidation and double strand breaks. Epithelialization also associated with redistribution of NRF2 and an altered interplay among p38, ATM, and the other kinases regulating the DNA damage response. Hence, hormonal regulation of OVOLs and chronic stress might permit epithelial differentiation and retard exit from dormancy, while altering redox homeostasis and permitting DNA damage accumulation, which may awaken dormant tumors.

cancer biology↗

CircPVT1 sponges miR-33a-5p unleashing the c-MYC/GLS1 metabolic axis in breast cancer

Altered metabolism is one of the cancer hallmarks. The role of circRNAs in cancer metabolism is still unexplored. Herein, we initially found that the expression of circPVT1 was significantly higher in tumoral tissues than in non-tumoral breast tissues. Basal like breast cancer patients with higher levels of circPVT1 exhibited shorter disease-free survival compared to those with lower expression. CircPVT1 ectopic expression rendered fully transformed MCF-10A immortalized breast cells and increased tumorigenicity of TNBC cell lines. Depletion of endogenous circPVT1 reduced tumorigenicity of SUM-159PT and MDA-MB-468 cells. 1H-NMR spectroscopy metabolic profiling of circPVT1 depleted breast cancer cell lines revealed reduced glycolysis and glutaminolitic fluxes. Conversely, MCF-10A cells stably overexpressing circPVT1 exhibited increased glutaminolysis. Mechanistically, circPVT1 sponges miR-33a-5p, a well know metabolic microRNA, which in turn releases c-MYC activity which promotes transcriptionally glutaminase, which converts glutamine to glutamate. CircPVT1 depletion synergizes with GLS1 inhibitors BPTES or CB839 to reduce cell viability of breast cancer cell lines and breast cancer-derived organoids. In aggregate, our findings unveil the circPVT1/miR-33a-5p/Myc/GLS1 axis as a pro-tumorigenic metabolic event sustaining breast cancer transformation with potential therapeutic implications.

cancer biology↗

Inactivation of p53 drives breast cancer brain metastasis by altering fatty acid metabolism

Brain metastasis (BM) is a dire prognosis across cancer types. It is largely unknown why some tumors metastasize to the brain whereas others do not. We analyzed genomic and transcriptional data from clinical samples of breast cancer BM (BCBM) and found that nearly all of them carried p53-inactivating genetic alterations through mutations, copy-number loss, or both. Importantly, p53 pathway activity was already perturbed in primary tumors giving rise to BCBM, often by loss of the entire 17p chromosome-arm. This association was recapitulated across other carcinomas. Experimentally, p53 knockout was sufficient to drastically increase BCBM formation and growth in vivo, providing a causal link between p53 inactivation and brain tropism. Mechanistically, p53-deficient BC cells exhibited altered lipid metabolism, particularly increased fatty acid (FA) synthesis and uptake, which are characteristic of brain-metastasizing cancer cells. FA metabolism was further enhanced by astrocytes in a p53-dependent manner, as astrocyte-conditioned medium increased FASN, SCD1, and CD36 expression and activity, and enhanced the survival, proliferation and migration of p53-deficient cancer cells. Consequently, these cells were more sensitive than p53-competent cells to FA synthesis inhibitors, in isogenic cell cultures, in BCBM-derived spheroids, and across dozens of BC cell lines. Lastly, a significant association was observed between p53 inactivation, astrocyte infiltration, and SCD1 expression in clinical human BCBM samples. In summary, our study identifies p53 inactivation as a driver of BCBM and potentially of BM in general; suggests a p53-dependent effect of astrocytes on BC cell behavior; and reveals FA metabolism as an underlying, therapeutically-targetable molecular mechanism.

cancer biology↗

Charting the transcriptomic landscape of primary and metastatic cancers in relation to their origin and target normal tissues

Metastasis is a leading cause of cancer-related deaths, yet understanding how metastatic tumors adapt from their origin to target tissues is challenging. To address this, we assessed whether primary and metastatic tumors resemble their tissue of origin or target tissue in terms of gene expression. We analyzed gene expression profiles from various cancer types, including single-cell and bulk RNA-seq data, in both paired and unpaired primary and metastatic patient cohorts. We quantified the transcriptomic distances between tumor samples and their normal tissues, revealing that primary tumors are more similar to their tissue of origin, while metastases shift towards the target tissue. Pathway-level analysis highlighted critical transcriptomic changes during metastasis. Notably, primary cancers exhibited higher activity in cancer hallmarks, including Activating Invasion and Metastasis, compared to metastatic cancers. This comprehensive landscape analysis provides insight into how cancer tumors adapt to their metastatic environments, providing a transcriptome-wide view of the processes involved.

cancer biology↗

Molecular profiling in HNSCC patients targets potential responsiveness to ICIs

Immunotherapy is emerging as a valid therapeutic strategy for various cancers although only a subset of patients responding to the therapy. The response to immunotherapy remains low for many cancer types because of poor ability to appropriately classify responding patients. We analyzed TCGA cohort of HNSCC patients in relation to a 26 immune gene set and cell types to define signaling pathways associated with resistance to immune checkpoint blockade. Results were validated on a cohort of 102 HNSCC patients under treatment with PD-L1 inhibitors and by in vitro experiments. Using bioinformatic approach, we observed a significant association between the gene set and TP53 gene status and other predictors of ICIs response in HNSCC patients. The presence of both TP53 mutation and co-mutations was associated with significantly higher levels of the immune gene expression than in lesions with only the TP53 mutated. We also observed that higher level of a MYC signature was associated with lower level of the immune gene expression. In vitro and cohort validation corroborated the evidence. SIGNIFICANCEImmune gene signature sets represent biomarkers to be implemented for the better classification of those HNSCC patients responsive to immunotherapy. A particular advantage of these biomarkers is the ability to characterize HNSCC patients using tumor tissues easily applicable in clinical setting.

cancer biology↗

TMPRSS2, a SARS-CoV-2 internalization protease is downregulated in head and neck cancer patients.

ObjectivesTwo of the main target tissues of SARS-coronavirus 2 are the oral cavity pharynx-larynx epithelium, the main virus entry site, and the lung epithelium. The virus enters host cells through binding of the Spike protein to ACE2 receptor and subsequent S priming by the TMPRSS2 protease. Herein we aim to assess differences in both ACE2 and TMPRSS2 expression in normal tissues from oral cavity-pharynx-larynx and lung tissues as well as neoplastic tissues from the same histological areas. The information provided in this study may contribute to better understanding of SARS-coronavirus 2 ability to interact with different biological systems and contributes to cumulative knowledge on potential mechanisms to inhibit its diffusion. Materials and MethodsThe study has been conducted using The Cancer Genome Atlas (TCGA) and the Regina Elena Institute (IRE) databases and validated by experimental model in HNSCC and Lung cancer cells. Data from one COVID19 positive patient who was operated on for HNSCC was also included. We have analyzed 478 tumor samples and 44 normal samples from TCGA HNSCC cohort for whom both miRNA and mRNA sequencing was available. The dataset included 391 HPV- and 85 HPV+ cases, with 331 P53 mutated and 147 P53 wild type cases respectively. 352 out of 478 samples were male and 126 female. In IRE cohort we analyzed 66 tumor samples with matched normal sample for miRNA profiling and 23 tumor\normal matched samples for mRNA profiling. 45 out of 66 tumors from IRE cohort were male and 21 female, 38 were P53 mutated and 27 wild type. Most patients (63 of 66) in IRE cohort were HPV negative. Normalized TCGA HNSCC gene expression and miRNA expression data were obtained from Broad Institute TCGA Genome Data Analysis Center (http://gdac.broadinstitute.org/). mRNA expression data from IRE cohort used in this study has been deposited to NCBIs Gene Expression Omnibus and is accessible through GEO series accession number GSE107591. In order to inference about potential molecular modulation of TMPRSS2, we also included miRNAs expression for the 66 IRE cohort matched tumor and normal samples from Agilent platform. DNA methylation data for TCGA tumors were obtained from Wanderer (http://maplab.imppc.org/wanderer/). We used miRWalk and miRNet web tools for miRNA-target interaction prediction and pathway enrichment analysis. The correlation and regression analyses as well as the miRNA and gene modulation and the survival analysis were conducted using Matlab R2019. ResultsTMPRSS2 expression in HNSCC was significantly reduced compared to the normal tissues and had a prognostic value in HNSCC patients. Reduction of TMPRSS2 expression was more evident in women than in men, in TP53 mutated versus wild TP53 tumors as well as in HPV negative patients compared to HPV positive counterparts. Functionally, we assessed the multivariate effect on TMPRSS2 in a single regression model. We observed that all variables had an independent effect on TMPRSS2 in HNSCC patients with HPV negative, TP53 mutated status and with elevated TP53-dependent Myc-target genes associated with low TMPRSS2 expression. Investigation of the molecular modulation of TMPRSS2 in both HNSCC and lung cancers revealed that expression of microRNAs targeting TMPRSS2 anti-correlated in both TCGA and IRE HNSCC datasets, while there was not evidence of TMPRSS2 promoter methylation in both tumor cohorts. Interestingly, the anti-correlation between microRNAs and TMPRSS2 expression was corroborated by testing this association in a SARS-CoV-2 positive HNSCC patient. ConclusionsCollectively, these findings suggest that tumoral tissues, herein exemplified by HNSCC and lung cancers might be more resistant to SARS-CoV-2 infection due to reduced expression of TMPRSS2. The protective mechanism might occur, at least partially, through the aberrant activation of TMPRSS2 targeting microRNAs; thereby providing strong evidence on the role of non-coding RNA molecule in host viral infection. These observations may help to better assess the frailty of SARS-CoV-2 positive cancer patients.

cancer biology↗

Division of labor between YAP and TAZ in non-small cell lung cancer

Lung cancer is the leading cause of cancer-related deaths worldwide. The paralogous transcriptional cofactors Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ, also called WWTR1), the main downstream effectors of the Hippo signal transduction pathway, are emerging as pivotal determinants of malignancy in lung cancer. Traditionally, studies have tended to consider YAP and TAZ as functionally redundant transcriptional cofactors, with similar biological impact. However, there is growing evidence that each of them also possesses distinct attributes. Here, we sought to systematically characterize the division of labor between YAP and TAZ in non-small cell lung cancer (NSCLC), the most common histological subtype of lung cancer. Employing representative NSCLC cell lines, as well as patient-derived data, we show that the two paralogs orchestrate non-overlapping transcription programs in this cancer type: whereas YAP preferentially regulates gene sets associated with cell division and cell cycle progression, TAZ preferentially regulates genes associated with extracellular matrix organization. Concordantly, depletion of YAP, but not TAZ, leads to growth arrest, while YAP overexpression promotes cell proliferation. Likewise, depletion of TAZ, but not YAP, compromises cell migration, whereas TAZ overexpression enhances migration. Importantly, the differential effects of YAP vs TAZ on key cellular processes are also associated with differential response to anti-cancer therapies. Uncovering the different activities and downstream effects of YAP and TAZ may thus facilitate better stratification of lung cancer patients for anti-cancer therapies.

cancer biology↗