Evaluation of global and intragenic hypomethylation in colorectal adenomas improves patient stratification and colorectal cancer risk prediction

Debernardi C, Libera L, Berrino E, Sahnane N, Chiaravalli AM, Laudi C, Berselli M, Sapino A, Sessa F, Venesio T, Furlan D.          

Clinical Epigenetics volume 13, Article number: 154 (2021)

Abstract

Background

Aberrant DNA hypomethylation of the long interspersed nuclear elements (LINE-1 or L1) has been recognized as an early event of colorectal transformation. Simultaneous genetic and epigenetic analysis of colorectal adenomas may be an effective and rapid strategy to identify key biological features leading to accelerated colorectal tumorigenesis. In particular, global and/or intragenic LINE-1 hypomethylation of adenomas may represent a helpful tool for improving colorectal cancer (CRC) risk stratification of patients after surgical removal of polyps. To verify this hypothesis, we analyzed a cohort of 102 adenomas derived from 40 high-risk patients (who developed CRC in a post-polypectomy of at least one year) and 43 low-risk patients (who did not develop CRC in a post-polypectomy of at least 5 years) for their main pathological features, the presence of hotspot variants in driver oncogenes (KRAS, NRAS, BRAF and PIK3CA), global (LINE-1) and intragenic (L1-MET) methylation status.

Results

In addition to a significantly higher adenoma size and an older patients’ age, adenomas from high-risk patients were more hypomethylated than those from low-risk patients for both global and intragenic LINE-1 assays. DNA hypomethylation, measured by pyrosequencing, was independent from other parameters, including the presence of oncogenic hotspot variants detected by mass spectrometry. Combining LINE-1 and L1-MET analyses and profiling the samples according to the presence of at least one hypomethylated assay improved the discrimination between high and low risk lesions (p = 0.005). Remarkably, adenomas with at least one hypomethylated assay identified the patients with a significantly (p < 0.001) higher risk of developing CRC. Multivariable analysis and logistic regression evaluated by the ROC curves proved that methylation status was an independent variable improving cancer risk prediction (p = 0.02).

Conclusions

LINE-1 and L1-MET hypomethylation in colorectal adenomas are associated with a higher risk of developing CRC. DNA global and intragenic hypomethylation are independent markers that could be used in combination to successfully improve the stratification of patients who enter a colonoscopy surveillance program.

Pursuit of Gene Fusions in Daily Practice: Evidence from Real-World Data in Wild-Type and Microsatellite Instable Patients

Berrino E, Bragoni A, Annaratone L, Fenocchio E, Carnevale-Schianca F, Garetto L, Aglietta M, Sarotto I, Casorzo L, Venesio T, Sapino A, Marchiò C. Pursuit of Gene Fusions in Daily Practice: Evidence from Real-World Data in Wild-Type and Microsatellite Instable Patients.

Cancers (Basel). 2021 Jul 5;13(13):3376. doi: 10.3390/cancers13133376.

Abstract

Agnostic biomarkers such as gene fusions allow to address cancer patients to targeted therapies; however, the low prevalence of these alterations across common malignancies poses challenges and needs a feasible and sensitive diagnostic process. RNA-based targeted next generation sequencing was performed on 125 samples of patients affected either by colorectal carcinoma, melanoma, or lung adenocarcinoma lacking genetic alterations in canonical driver genes, or by a colorectal carcinoma with microsatellite instability. Gene fusion rates were compared with in silico data from MSKCC datasets. For NTRK gene fusion detection we also employed a multitarget qRT-PCR and pan-TRK immunohistochemistry. Gene fusions were detected in 7/55 microsatellite instable colorectal carcinomas (12.73%), and in 4/70 of the "gene driver free" population (5.71%: 3/28 melanomas, 10.7%, and 1/12 lung adenocarcinomas, 8.3%). Fusion rates were significantly higher compared with the microsatellite stable and "gene driver positive" MSKCC cohorts. Pan-TRK immunohistochemistry showed 100% sensitivity, 91.7% specificity, and the occurrence of heterogeneous and/or subtle staining patterns. The enrichment of gene fusions in this "real-world" cohort highlights the feasibility of a workflow applicable in clinical practice. The heterogeneous expression in NTRK fusion positive tumours unveils challenging patterns to recognize and raises questions on the effective translation of the chimeric protein.

Keywords: NTRK genes; agnostic biomarker; colorectal carcinoma; gene fusions; gene panels; immunohistochemistry; lung adenocarcinomas; melanoma; next generation sequencing; precision medicine.

Basic principles of biobanking: from biological samples to precision medicine for patients

Annaratone L, De Palma G, Bonizzi G, Sapino A, Botti G, Berrino E, Mannelli C, Arcella P, Di Martino S, Steffan A, Daidone MG, Canzonieri V, Parodi B, Paradiso AV, Barberis M, Marchiò C

Virchows Arch. 2021 Aug;479(2):233-246. doi: 10.1007/s00428-021-03151-0. Epub 2021 Jul 13.

Abstract

The term "biobanking" is often misapplied to any collection of human biological materials (biospecimens) regardless of requirements related to ethical and legal issues or the standardization of different processes involved in tissue collection. A proper definition of biobanks is large collections of biospecimens linked to relevant personal and health information (health records, family history, lifestyle, genetic information) that are held predominantly for use in health and medical research. In addition, the International Organization for Standardization, in illustrating the requirements for biobanking (ISO 20387:2018), stresses the concept of biobanks being legal entities driving the process of acquisition and storage together with some or all of the activities related to collection, preparation, preservation, testing, analysing and distributing defined biological material as well as related information and data. In this review article, we aim to discuss the basic principles of biobanking, spanning from definitions to classification systems, standardization processes and documents, sustainability and ethical and legal requirements. We also deal with emerging specimens that are currently being generated and shaping the so-called next-generation biobanking, and we provide pragmatic examples of cancer-associated biobanking by discussing the process behind the construction of a biobank and the infrastructures supporting the implementation of biobanking in scientific research.

Keywords: Biobanking; Biospecimens; Cell lines; Preanalytical phase; Standardization; Tissue specimens.

Castration-Induced Downregulation of SPARC in Stromal Cells Drives Neuroendocrine Differentiation of Prostate Cancer

Enriquez C, Cancila V, Ferri R, Sulsenti R, Fischetti I, Milani M, Ostano P, Gregnanin I, Mello-Grand M, Berrino E, Bregni M, Renne G, Tripodo C, Colombo MP, Jachetti E.

Cancer Res. 2021 Aug 15;81(16):4257-4274. doi: 10.1158/0008-5472.CAN-21-0163. Epub 2021 Jun 21.

Abstract

Fatal neuroendocrine differentiation (NED) of castration-resistant prostate cancer is a recurrent mechanism of resistance to androgen deprivation therapies (ADT) and antiandrogen receptor pathway inhibitors (ARPI) in patients. The design of effective therapies for neuroendocrine prostate cancer (NEPC) is complicated by limited knowledge of the molecular mechanisms governing NED. The paucity of acquired genomic alterations and the deregulation of epigenetic and transcription factors suggest a potential contribution from the microenvironment. In this context, whether ADT/ARPI induces stromal cells to release NED-promoting molecules and the underlying molecular networks are unestablished. Here, we utilized transgenic and transplantable mouse models and coculture experiments to unveil a novel tumor-stroma cross-talk that is able to induce NED under the pressure of androgen deprivation. Castration induced upregulation of GRP78 in tumor cells, which triggers miR29-b-mediated downregulation of the matricellular protein SPARC in the nearby stroma. SPARC downregulation enabled stromal cells to release IL6, a known inducer of NED. A drug that targets GRP78 blocked NED in castrated mice. A public, human NEPC gene expression dataset showed that Hspa5 (encoding for GRP78) positively correlates with hallmarks of NED. Finally, prostate cancer specimens from patients developing local NED after ADT showed GRP78 upregulation in tumor cells and SPARC downregulation in the stroma. These results point to GRP78 as a potential therapeutic target and to SPARC downregulation in stromal cells as a potential early biomarker of tumors undergoing NED. SIGNIFICANCE: Tumor-stroma cross-talk promotes neuroendocrine differentiation in prostate cancer in response to hormone therapy via a GRP78/SPARC/IL6 axis, providing potential therapeutic targets and biomarkers for neuroendocrine prostate cancer.

COVseq is a cost-effective workflow for mass-scale SARS-CoV-2 genomic surveillance

Simonetti M, Zhang N, Harbers L, Milia MG, Brossa S, Huong Nguyen TT, Cerutti F, Berrino E, Sapino A, Bienko M, Sottile A, Ghisetti V, Crosetto N.

Nature Communications volume 12, Article number: 3903 (2021) 

Abstract

While mass-scale vaccination campaigns are ongoing worldwide, genomic surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical to monitor the emergence and global spread of viral variants of concern (VOC). Here, we present a streamlined workflow—COVseq—which can be used to generate highly multiplexed sequencing libraries compatible with Illumina platforms from hundreds of SARS-CoV-2 samples in parallel, in a rapid and cost-effective manner. We benchmark COVseq against a standard library preparation method (NEBNext) on 29 SARS-CoV-2 positive samples, reaching 95.4% of concordance between single-nucleotide variants detected by both methods. Application of COVseq to 245 additional SARS-CoV-2 positive samples demonstrates the ability of the method to reliably detect emergent VOC as well as its compatibility with downstream phylogenetic analyses. A cost analysis shows that COVseq could be used to sequence thousands of samples at less than 15 USD per sample, including library preparation and sequencing costs. We conclude that COVseq is a versatile and scalable method that is immediately applicable for SARS-CoV-2 genomic surveillance and easily adaptable to other pathogens such as influenza viruses.

High BRAF variant allele frequencies are associated with distinct pathological features and responsiveness to target therapy in melanoma patients

Berrino E, Balsamo A, Pisacane A, Gallo S, Becco P, Miglio U, Caravelli D, Poletto S, Paruzzo L, Debernardi C, Piccinelli C, Zaccagna A, Rescigno P, Aglietta M, Sapino A, Carnevale-Schianca F, Venesio T.

ESMO Open. 2021 Jun;6(3):100133. doi: 10.1016/j.esmoop.2021.100133. Epub 2021 May 10.

Abstract

Background: BRAF mutant melanoma patients are commonly treated with anti-BRAF therapeutic strategies. However, many factors, including the percentage of BRAF-mutated cells, may contribute to the great variability in patient outcomes.

Patients and methods: The BRAF variant allele frequency (VAF; defined as the percentage of mutated alleles) of primary and secondary melanoma lesions, obtained from 327 patients with different disease stages, was assessed by pyrosequencing. The BRAF mutation rate and VAF were then correlated with melanoma pathological features and patients' clinical characteristics. Kaplan-Meier curves were used to study the correlations between BRAF VAF, overall survival (OS), and progression-free survival (PFS) in a subset of 62 patients treated by anti-BRAF/anti-MEK therapy after metastatic progression.

Results: A highly heterogeneous BRAF VAF was identified (3%-90%). Besides being correlated with age, a higher BRAF VAF level was related to moderate lymphocytic infiltration (P = 0.017), to melanoma thickness according to Clark levels, (level V versus III, P = 0.004; level V versus IV, P = 0.04), to lymph node metastases rather than cutaneous (P = 0.04) or visceral (P = 0.03) secondary lesions. In particular, a BRAF VAF >25% was significantly associated with a favorable outcome in patients treated with the combination of anti-BRAF/anti-MEK drug (OS P = 0.04; PFS P = 0.019), retaining a significant value as an independent factor for the OS and the PFS in the multivariate analysis (P = 0.014 and P = 0.003, respectively).

Conclusion: These results definitively support the role of the BRAF VAF as a potential prognostic and predictive biomarker in melanoma patients in the context of BRAF inhibition.

Keywords: BRAF mutations; increased survival; melanoma; variant allele frequency.

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