{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T12:31:27Z","timestamp":1762432287307,"version":"build-2065373602"},"reference-count":29,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2022,10,18]],"date-time":"2022-10-18T00:00:00Z","timestamp":1666051200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100007076","name":"AIRC\u2014Associazione Italiana Ricerca sul Cancro","doi-asserted-by":"publisher","award":["IG2014-15839","IG2018-22059","RC-2022-2773355"],"award-info":[{"award-number":["IG2014-15839","IG2018-22059","RC-2022-2773355"]}],"id":[{"id":"10.13039\/501100007076","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003196","name":"Ministero dell\u2019Universit\u00e0 e della Ricerca","doi-asserted-by":"publisher","award":["IG2014-15839","IG2018-22059","RC-2022-2773355"],"award-info":[{"award-number":["IG2014-15839","IG2018-22059","RC-2022-2773355"]}],"id":[{"id":"10.13039\/501100003196","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Associazione Italiana contro le Leucemie, Linfomi e Mieloma","award":["IG2014-15839","IG2018-22059","RC-2022-2773355"],"award-info":[{"award-number":["IG2014-15839","IG2018-22059","RC-2022-2773355"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>DNA microarrays and RNA-based sequencing approaches are considered important discovery tools in clinical medicine. However, cross-platform reproducibility studies undertaken so far have highlighted that microarrays are not able to accurately measure gene expression, particularly when they are expressed at low levels. Here, we consider the employment of a digital PCR assay (ddPCR) to validate a gene signature previously identified by gene expression profile. This signature included ten Hedgehog (HH) pathways\u2019 genes able to stratify multiple myeloma (MM) patients according to their self-renewal status. Results show that the designed assay is able to validate gene expression data, both in a retrospective as well as in a prospective cohort. In addition, the plasma cells\u2019 differentiation status determined by ddPCR was further confirmed by other techniques, such as flow cytometry, allowing the identification of patients with immature plasma cells\u2019 phenotype (i.e., expressing CD19+\/CD81+ markers) upregulating HH genes, as compared to others, whose plasma cells lose the expression of these markers and were more differentiated. To our knowledge, this is the first technical report of gene expression data validation by ddPCR instead of classical qPCR. This approach permitted the identification of a Maturation Index through the integration of molecular and phenotypic data, able to possibly define upfront the differentiation status of MM patients that would be clinically relevant in the future.<\/jats:p>","DOI":"10.3390\/ijms232012450","type":"journal-article","created":{"date-parts":[[2022,10,18]],"date-time":"2022-10-18T21:18:02Z","timestamp":1666127882000},"page":"12450","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Identification of a Maturation Plasma Cell Index through a Highly Sensitive Droplet Digital PCR Assay Gene Expression Signature Validation in Newly Diagnosed Multiple Myeloma Patients"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8196-8707","authenticated-orcid":false,"given":"Marina","family":"Martello","sequence":"first","affiliation":[{"name":"IRCCS Azienda Ospedaliero-Universitaria di Bologna, Istituto di Ematologia \u201cSer\u00e0gnoli\u201d, 40138 Bologna, Italy"},{"name":"Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4828-6955","authenticated-orcid":false,"given":"Vincenza","family":"Solli","sequence":"additional","affiliation":[{"name":"IRCCS Azienda Ospedaliero-Universitaria di Bologna, Istituto di Ematologia \u201cSer\u00e0gnoli\u201d, 40138 Bologna, Italy"},{"name":"Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7263-8415","authenticated-orcid":false,"given":"Rosalinda","family":"Termini","sequence":"additional","affiliation":[{"name":"Clinica Universidad de Navarra, Centro de Investigaci\u00f3n M\u00e9dica Aplicada (CIMA), Instituto de Investigacion Sanitaria de Navarra (IDISNA), CCUN, CIBER-ONC Numbers CB16\/12\/00369, CB16\/12\/00489, 31001 Pamplona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ajsi","family":"Kanapari","sequence":"additional","affiliation":[{"name":"IRCCS Azienda Ospedaliero-Universitaria di Bologna, Istituto di Ematologia \u201cSer\u00e0gnoli\u201d, 40138 Bologna, Italy"},{"name":"Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3185-7456","authenticated-orcid":false,"given":"Daniel","family":"Remondini","sequence":"additional","affiliation":[{"name":"Department of Physics and Astronomy, DIFA\u2014University of Bologna, 40126 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3314-0037","authenticated-orcid":false,"given":"Enrica","family":"Borsi","sequence":"additional","affiliation":[{"name":"IRCCS Azienda Ospedaliero-Universitaria di Bologna, Istituto di Ematologia \u201cSer\u00e0gnoli\u201d, 40138 Bologna, Italy"},{"name":"Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0753-1248","authenticated-orcid":false,"given":"Andrea","family":"Poletti","sequence":"additional","affiliation":[{"name":"IRCCS Azienda Ospedaliero-Universitaria di Bologna, Istituto di Ematologia \u201cSer\u00e0gnoli\u201d, 40138 Bologna, Italy"},{"name":"Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6690-2590","authenticated-orcid":false,"given":"Silvia","family":"Armuzzi","sequence":"additional","affiliation":[{"name":"IRCCS Azienda Ospedaliero-Universitaria di Bologna, Istituto di Ematologia \u201cSer\u00e0gnoli\u201d, 40138 Bologna, Italy"},{"name":"Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Barbara","family":"Taurisano","sequence":"additional","affiliation":[{"name":"IRCCS Azienda Ospedaliero-Universitaria di Bologna, Istituto di Ematologia \u201cSer\u00e0gnoli\u201d, 40138 Bologna, Italy"},{"name":"Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, 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