1. |
- Andersson, Natalie, et al.
(author)
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Inactivation of RB1, CDKN2A and TP53 have distinct effects on genomic stability at side-by-side comparison in karyotypically normal cells
- 2023
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In: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 62:2, s. 93-100
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Journal article (peer-reviewed)abstract
- Chromosomal instability is a common feature in malignant tumors. Previous studies have indicated that inactivation of the classical tumor suppressor genes RB1, CDKN2A and TP53 may contribute to chromosomal aberrations in cancer by disrupting different aspects of the cell cycle and DNA damage checkpoint machinery. We performed a side-by-side comparison of how inactivation of each of these genes affected chromosomal stability in vitro. Using CRISPR-Cas9 technology, RB1, CDKN2A and TP53 were independently knocked out in karyotypically normal immortalized cells, after which these cells were followed over time. Bulk RNA sequencing revealed a distinct phenotype with upregulation of pathways related to cell cycle control and proliferation in all three knockouts. Surprisingly, the RB1 and CDKN2A knocked out cell lines did not harbor more copy number aberrations than wild-type cells, despite culturing for months. The TP53-knocked out cells, in contrast, showed a massive amount of copy number alterations and saltatory evolution through whole genome duplication. This side-by-side comparison indicated that the effects on chromosomal stability from inactivation of RB1 and CDKN2A are negligible compared to inactivation of TP53, under the same conditions in a non-stressful environment, even though partly overlapping regulatory pathways are affected.
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2. |
- Andersson, Natalie, et al.
(author)
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DEVOLUTION—A method for phylogenetic reconstruction of aneuploid cancers based on multiregional genotyping data
- 2021
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In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 4
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Journal article (peer-reviewed)abstract
- Phylogenetic reconstruction of cancer cell populations remains challenging. There is a particular lack of tools that deconvolve clones based on copy number aberration analyses of multiple tumor biopsies separated in time and space from the same patient. This has hampered investigations of tumors rich in aneuploidy but few point mutations, as in many childhood cancers and high-risk adult cancer. Here, we present DEVOLUTION, an algorithm for subclonal deconvolution followed by phylogenetic reconstruction from bulk genotyping data. It integrates copy number and sequencing information across multiple tumor regions throughout the inference process, provided that the mutated clone fraction for each mutation is known. We validate DEVOLUTION on data from 56 pediatric tumors comprising 253 tumor biopsies and show a robust performance on simulations of bulk genotyping data. We also benchmark DEVOLUTION to similar bioinformatic tools using an external dataset. DEVOLUTION holds the potential to facilitate insights into the development, progression, and response to treatment, particularly in tumors with high burden of chromosomal copy number alterations.
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3. |
- Edsjö, Anders, et al.
(author)
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Building a precision medicine infrastructure at a national level : The Swedish experience
- 2023
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In: Cambridge Prisms: Precision Medicine. - : Cambridge University Press. - 2752-6143. ; 1
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Research review (peer-reviewed)abstract
- Precision medicine has the potential to transform healthcare by moving from one-size-fits-all to personalised treatment and care. This transition has been greatly facilitated through new high-throughput sequencing technologies that can provide the unique molecular profile of each individual patient, along with the rapid development of targeted therapies directed to the Achilles heels of each disease. To implement precision medicine approaches in healthcare, many countries have adopted national strategies and initiated genomic/precision medicine initiatives to provide equal access to all citizens. In other countries, such as Sweden, this has proven more difficult due to regionally organised healthcare. Using a bottom-up approach, key stakeholders from academia, healthcare, industry and patient organisations joined forces and formed Genomic Medicine Sweden (GMS), a national infrastructure for the implementation of precision medicine across the country. To achieve this, Genomic Medicine Centres have been established to provide regionally distributed genomic services, and a national informatics infrastructure has been built to allow secure data handling and sharing. GMS has a broad scope focusing on rare diseases, cancer, pharmacogenomics, infectious diseases and complex diseases, while also providing expertise in informatics, ethical and legal issues, health economy, industry collaboration and education. In this review, we summarise our experience in building a national infrastructure for precision medicine. We also provide key examples how precision medicine already has been successfully implemented within our focus areas. Finally, we bring up challenges and opportunities associated with precision medicine implementation, the importance of international collaboration, as well as the future perspective in the field of precision medicine.
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4. |
- Gisselsson Nord, David, et al.
(author)
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Wargaming cancer: a strategy for future precision oncology?
- 2023
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In: Trends in Cancer. - 2405-8025. ; 9:9, s. 697-699
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Journal article (peer-reviewed)abstract
- Development of drug resistance is a mounting problem in precision oncology, demanding a rethink of treatment strategy. We here apply concepts from military theory and espionage to the battle-like dynamics between cancer and its host, thereby identifying system vulnerabilities in cancer and ways of tricking cancer’s evolution into dead ends.
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5. |
- Peña-Martínez, Pablo, et al.
(author)
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Interleukin 4 promotes phagocytosis of murine leukemia cells counteracted by CD47 upregulation
- 2022
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In: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 107:4, s. 816-824
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Journal article (peer-reviewed)abstract
- Cytokines are key regulators of tumor immune surveillance by controlling immune cell activity. Here, we investigated whether interleukin 4 (IL4) has antileukemic activity via immune-mediated mechanisms in an in vivo murine model of acute myeloid leukemia driven by the MLL-AF9 fusion gene. Although IL4 strongly inhibited leukemia development in immunocompetent mice, the effect was diminished in immune-deficient recipient mice, demonstrating that the antileukemic effect of IL4 in vivo is dependent on the host immune system. Using flow cytometric analysis and immunohistochemistry, we revealed that the antileukemic effect of IL4 coincided with an expansion of F4/80+ macrophages in the bone marrow and spleen. To elucidate whether this macrophage expansion was responsible for the antileukemic effect, we depleted macrophages in vivo with clodronate liposomes. Macrophage depletion eliminated the antileukemic effect of IL4, showing that macrophages mediated the IL4-induced killing of leukemia cells. In addition, IL4 enhanced murine macrophage-mediated phagocytosis of leukemia cells in vitro. Global transcriptomic analysis of macrophages revealed an enrichment of signatures associated with alternatively activated macrophages and increased phagocytosis upon IL4 stimulation. Notably, IL4 concurrently induced Stat6-dependent upregulation of CD47 on leukemia cells, which suppressed macrophage activity. Consistent with this finding, combining CD47 blockade with IL4 stimulation enhanced macrophage-mediated phagocytosis of leukemia cells. Thus, IL4 has two counteracting roles in regulating phagocytosis in mice; enhancing macrophage-mediated killing of leukemia cells, but also inducing CD47 expression that protects target cells from excessive phagocytosis. Taken together, our data suggest that combined strategies that activate macrophages and block CD47 have therapeutic potential in acute myeloid leukemia.
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6. |
- Petersson, Alexandra, et al.
(author)
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Branching copy number evolution and parallel immune profiles across the regional tumor space of resected pancreatic cancer
- 2022
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In: Molecular Cancer Research. - 1557-3125. ; 20:5, s. 749-761
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Journal article (peer-reviewed)abstract
- Pancreatic ductal adenocarcinoma (PDAC) remains a highly lethal disease. The only option for curative treatment is resection of the tumor followed by standard adjuvant chemotherapy. Yet, early relapse due to chemoresistance is almost inevitable. Herein, we delineated the genetic intratumor heterogeneity in resected PDAC, with the aim to identify evolutionary patterns that may be associated with overall survival (OS) following treatment with curative intent. Potential relationships with the adjacent immune microenvironment were also examined. The genetic and immune landscapes of the regional tumor space were analyzed in nine patients with resected PDAC. Targeted deep sequencing and genome wide SNP array were followed by clonal deconvolution and phylogenetic analysis. A mathematical complexity score was developed to calculate the network extent of each phylogeny. Spatial variation in abundancy and tumor nest infiltration of immune cells was analyzed by double immunohistochemical staining. Copy number heterogeneity was denoted as the major contributing factor to the branching architectures of the produced phylogenetic trees. Increased tree complexity was significantly inversely associated with OS, and larger regional maximum aberrations (higher treetops) were associated with increased PD-L1 expression on tumor cells. Contrastingly, a FREM1 gene amplification, found in one patient, coincided with a particularly vigorous immune response. Findings from this limited case series suggest that complex evolutionary patterns may be associated with a shorter survival in surgically treated PDAC patients. Some hypothesis-generating associations with the surrounding immune microenvironment were also detected.Implications: Evolutionary copy number patterns may be associated with survival in patients with resected PDAC.
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8. |
- Siesing, Christina, et al.
(author)
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Delineating the intra-patient heterogeneity of molecular alterations in treatment-naïve colorectal cancer with peritoneal carcinomatosis
- 2022
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In: Modern Pathology. - : Elsevier BV. - 1530-0285 .- 0893-3952. ; 35:7, s. 979-988
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Journal article (peer-reviewed)abstract
- In a non-negligible number of patients with metastatic colorectal cancer (mCRC), the peritoneum is the predominant site of dissemination. Cure can be achieved by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), but this procedure is associated with long-term morbidity and high relapse rates. Thus, there is a pressing need for improved therapeutic strategies and complementary biomarkers. The present study explored the molecular heterogeneity in mCRC with peritoneal carcinomatosis (PC), and the potential clinical implications thereof. Multi-region immunohistochemical profiling and deep targeted DNA-sequencing was performed on chemotherapy-naïve tumours from seven patients with synchronous colorectal PC who underwent CRS and HIPEC. In total, 88 samples (5-19 per patient) were analysed, representing primary tumour, lymph node metastases, tumour deposits, PC and liver metastases. Expression of special AT-rich sequence-binding protein 2 (SATB2), a marker of colorectal lineage, was lacking in the majority of cases, and a conspicuous intra-patient heterogeneity was denoted for expression of the proposed prognostic and predictive biomarker RNA-binding motif protein 3 (RBM3). Loss of mismatch repair proteins MLH1 and PSM2, observed in one case, was concordant with microsatellite instability and the highest tumour mutational burden. When present in a patient, mutations in key CRC driver genes, i.e., KRAS, APC and TP53, were homogenously distributed across all samples, while less common mutations were more heterogenous. On the same note, copy number variations showed intra-patient as well inter-patient heterogeneity. In two out of seven cases, hierarchical clustering revealed that samples from the PC and lymph node metastases were more similar to each other than to the primary tumour. In summary, these findings should encourage additional studies addressing the potential distinctiveness of mCRC with PC, which might pave the way for improved personalized treatment of these patients.
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10. |
- Zaigham, Mehreen, et al.
(author)
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Intrauterine vertical SARS-CoV-2 infection : a case confirming transplacental transmission followed by divergence of the viral genome
- 2021
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In: BJOG: An International Journal of Obstetrics & Gynaecology. - : Wiley. - 1471-0528 .- 1470-0328. ; 128:8, s. 1388-1394
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Journal article (peer-reviewed)abstract
- A 27-year-old woman (gravida 2, para 1) was transported to the regional university hospital in gestational week (GW) 34 + 4 due to a three-day history of fever, abdominal pain and reduced foetal movements. She had developed a dry cough one day prior to the admission (Figure S1). The woman, was slightly overweight (BMI 27 kg/m2 ) but otherwise healthy. She had normal antenatal check-ups and an obstetric ultrasound at GW 32 + 2 showed a normal foetal weight deviation of +8%1 .
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