Publications by authors named "Erik Vassella"

Evasion of programmed cell death (PCD) is a hallmark of cancer, yet the mechanisms underlying resistance to ferroptosis - an iron-dependent form of PCD triggered by excessive lipid peroxidation - remain incompletely understood. Here, we identify a previously unrecognized nucleolar-mitochondrial signaling axis that promotes ferroptosis resistance in pleural mesothelioma (PM) and potentially other cancers. This pathway involves RNA polymerase I (PolI) catalytic subunit A (POLR1A) and mitochondrial transcription factor A (TFAM), which together regulate mitophagy and intracellular iron metabolism to suppress ferroptosis.

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Purpose: Research suggests that metformin may reduce tumor hypoxia, rendering it a potential radiosensitizer. This study investigated metformin's effect on hypoxia-associated gene expression in oral cavity squamous cell carcinoma (OCSCC).

Methods: In this prospective trial, non-diabetic patients with OCSCC scheduled for curative surgery received preoperative metformin for 10 to 14 days.

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: The distinction of clinically uncertain, poorly differentiated liver masses into primary liver cancer (PLC) of cholangiocytic origin (intrahepatic cholangiocarcinoma; CCA) or hepatocellular origin (hepatocellular carcinoma; HCC) vs. metastasis is highly relevant to guiding patient treatment. Protocols differ in terms of resection, local ablation, liver transplantation, or systemic therapies with immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors (TKIs).

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Aims: Mutations affecting exon 3 of the β-catenin () gene result in constitutive activation of WNT signalling and are a diagnostic hallmark of several tumour entities including desmoid-type fibromatosis. They also define clinically relevant tumour subtypes within certain entities, such as endometrioid carcinoma. In diagnostics, β-catenin immunohistochemistry is widely used as a surrogate for mutations.

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Somatic variant testing through next-generation sequencing (NGS) is well integrated into Swiss molecular pathology laboratories and has become a standard diagnostic method for numerous indications in cancer patient care. Currently, there is a wide variation in reporting practices within our country, and as patients move between different hospitals, it is increasingly necessary to standardize NGS reports to ease their reinterpretation. Additionally, as many different stakeholders-oncologists, hematologists, geneticists, pathologists, and patients-have access to the NGS report, it needs to contain comprehensive and detailed information in order to answer the questions of experts and avoid misinterpretation by non-experts.

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Article Synopsis
  • PIK3CA gene variants are linked to vascular malformations, and this study aimed to analyze their phenotypes, locations within the gene, and frequency in patients with these conditions.
  • Data was collected from 558 patients with vascular malformations between 2008 and 2022, with genetic testing performed on biopsy samples starting in 2020, leading to 89 patients being included by June 2022.
  • The research found 25 PIK3CA variants, predominantly in nonsyndromic (simple/combined) vascular malformations, with notable hotspot and non-hotspot variants and significant differences in variant frequency between syndromic and nonsyndromic cases, highlighting the genetic diversity underlying these conditions.
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Spheroid cultures of cancer cell lines or primary cells represent a more clinically relevant model for predicting therapy response compared to two-dimensional cell culture. However, current live-dead staining protocols used for treatment response in spheroid cultures are often expensive, toxic to the cells, or limited in their ability to monitor therapy response over an extended period due to reduced stability. In our study, we have developed a cost-effective method utilizing calcein-AM and Helix NP™ Blue for live-dead staining, enabling the monitoring of therapy response of spheroid cultures for up to 10 days.

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Arteriovenous malformations (AVM) are benign vascular anomalies prone to pain, bleeding, and progressive growth. AVM are mainly caused by mosaic pathogenic variants of the RAS-MAPK pathway. However, a causative variant is not identified in all patients.

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  • * This research utilized imaging Mueller polarimetry to analyze 45 measurements from 27 fresh brain tumor samples, focusing on gliomas, and aimed to improve tumor delineation during neurosurgery.
  • * The study found differences in polarimetric properties between tumor types and brain tissues, and lays groundwork for using machine learning algorithms to enhance brain tumor segmentation and intraoperative diagnosis.
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A 44-year-old female patient with a familial adenomatous polyposis (FAP) was diagnosed with a cribriform morular thyroid carcinoma (CMTC). We observed within the very necrotic tumor a small but distinct poorly differentiated carcinomatous component. As expected, next generation sequencing of both components revealed a homozygous APC mutation and in addition, a TERT promoter mutation.

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Significance: Imaging Mueller polarimetry (IMP) appears as a promising technique for real-time delineation of healthy and neoplastic tissue during neurosurgery. The training of machine learning algorithms used for the image post-processing requires large data sets typically derived from the measurements of formalin-fixed brain sections. However, the success of the transfer of such algorithms from fixed to fresh brain tissue depends on the degree of alterations of polarimetric properties induced by formalin fixation (FF).

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Article Synopsis
  • Homozygous deletion of the CDKN2A/B locus is a negative prognostic marker in diffuse gliomas, and its detection is vital for patient outcomes.
  • The study evaluated the effectiveness of MTAP and p16 immunostaining as alternative methods for identifying CDKN2A/B deletions compared to traditional techniques like CNV analysis, revealing high sensitivity and specificity.
  • Results indicate that loss of MTAP is linked to significantly shorter survival rates in various glioma types, emphasizing the importance of MTAP immunostaining as a diagnostic tool in glioma assessments.
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Serine/Threonine protein phosphatase 2A (PP2A) is a heterotrimeric (or occasionally, heterodimeric) phosphatase with pleiotropic functions and ubiquitous expression. Despite the fact that they all contribute to protein dephosphorylation, multiple PP2A complexes exist which differ considerably by their subcellular localization and their substrate specificity, suggesting diverse PP2A functions. PP2A complex formation is tightly regulated by means of gene expression regulation by transcription factors, microRNAs, and post-translational modifications.

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Introduction: Expression of programmed death-ligand 1 (PD-L1) is the only routinely used tissue biomarker for predicting response to programmed cell death protein 1/PD-L1 inhibitors. It is to date unclear whether PD-L1 expression is preserved in brain metastases (BMs).

Methods: In this single-center, retrospective study, we evaluated PD-L1 expression using the SP263 assay in consecutively resected BMs of lung carcinomas and paired primary tumors, diagnosed from 2000 to 2015, with correlation to clinicopathological and molecular tumor and patient characteristics.

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  • Adult-type diffuse gliomas, particularly those classified as CNS WHO grade 4, are highly aggressive brain tumors that pose significant challenges for treatment; this study analyzed their genetic and molecular changes after recurrence.
  • The research involved sequencing and profiling to uncover alterations in recurrent gliomas, revealing that 75% of patients had early branching evolution, along with changes in mutational patterns and increased TGF-β signaling.
  • Findings indicate that TGF-β plays a critical role in the recurrence of gliomas and could guide future therapies, particularly with TGF-β inhibitors potentially aiding in overcoming resistance to chemoradiation treatments.
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Background: Glioblastomas with methylation of the promoter region of the O(6)-methylguanine-DNA methyltransferase (MGMT) gene exhibit increased sensitivity to alkylating chemotherapy. Quantitative assessment of the MGMT promoter methylation status might provide additional prognostic information. The aim of our study was to determine a quantitative methylation threshold for better survival among patients with glioblastomas.

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Background And Objectives: Experimental studies indicate shared molecular pathomechanisms in cerebral hypoxia-ischemia and autoimmune neuroinflammation. This has led to clinical studies investigating the effects of immunomodulatory therapies approved in multiple sclerosis on inflammatory damage in stroke. So far, mutual and combined interactions of autoimmune, CNS antigen-specific inflammatory reactions and cerebral ischemia have not been investigated so far.

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Improved survival rates for prostate cancer through more effective therapies have also led to an increase in the diagnosis of metastases to infrequent locations such as the brain. Here we investigate the repertoire of somatic genetic alterations present in brain metastases from 51 patients with prostate cancer brain metastases (PCBM). We highlight the clonal evolution occurring in PCBM and demonstrate an increased mutational burden, concomitant with an enrichment of the homologous recombination deficiency mutational signature in PCBM compared to non-brain metastases.

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Background: Brain metastases present a significant complication in lung cancer with an unmet therapeutic need.

Methods: In this single-centre, retrospective study, we genotyped a clinico-pathologically well-annotated cohort of consecutively resected brain metastases of lung adenocarcinomas and paired primary tumours, diagnosed from 2000 to 2015, using the Ion Torrent Oncomine Comprehensive Cancer Panel v3.

Results: Among 444 consecutive brain metastases, 210 (49%) originated from lung cancer.

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Recent data suggest that Pancreatic Neuroendocrine Tumours (PanNETs) originate from α- or β-cells of the islets of Langerhans. The majority of PanNETs are non-functional and do not express cell-type specific hormones. In the current study we examine whether tumour DNA methylation (DNAme) profiling combined with genomic data is able to identify cell of origin and to reveal pathways involved in PanNET progression.

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Among the most challenging diagnostic issues in surgical neuropathology is the distinction between scant infiltration by diffuse gliomas and reactive gliosis. The best documented ancillary marker to establish a definitive diagnosis of glioma in this setting is the identification of hotspot mutations in the isocitrate dehydrogenase 1 and 2 (IDH1/IDH2) genes, which is limited, however, by the low prevalence of these mutations in gliomas of elderly adults. Since telomerase reverse transcriptase (TERT) promoter mutations are present in the vast majority of IDH-wildtype diffuse gliomas, we hypothesized that combined analysis of IDH and TERT might overcome these limitations.

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Oncogenic KRAS mutations comprise the largest subset of lung cancer defined by genetic alterations, but in the clinic no targeted therapies are available that effectively control mutational KRAS activation. Consequently, patients with KRAS-driven tumors are routinely treated with cytotoxic chemotherapy, which is often transiently effective owing to development of drug resistance. In this study, we show that hyperactivated mammalian target of rapamycin (mTOR) pathway is a characteristic hallmark of KRAS-mutant lung adenocarcinoma after chemotherapy treatment, and that KRAS-mutant lung cancer cells rely on persistent mTOR signaling to resist chemotherapeutic drugs.

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Bladder outlet obstruction (BOO) and the ensuing clinical lower urinary tract dysfunction are common in elderly patients. BOO is accompanied by urodynamic changes in bladder function and leads to organ fibrosis and ultimately loss of contractility. Comprehensive transcriptome analysis of bladder samples from human patients with different urodynamically defined phenotypes of BOO revealed tumor necrosis factor (TNF)-α as the top upstream signaling pathway regulator.

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Next-generation sequencing (NGS) enables parallel analysis of multiple genomic targets. The increasing demand for NGS-based multiplexed molecular diagnostics requires standardized protocols and recommendations to ensure reproducibility and accuracy of test results for routine clinical decision making. However, the lack of clinical NGS data from multi-laboratory tests and the absence of inter-laboratory comparisons have hampered the establishment of instructive clinical NGS standards.

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