Browsing by Subject "Ki67"

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    Analytical validation of a standardized scoring protocol for Ki67: phase 3 of an international multicenter collaboration
    (Nature, 2016) Leung, Samuel C. Y.; Nielsen, Torsten O.; Zabaglo, Lila; Arun, Indu; Badve, Sunil S.; Bane, Anita L.; Bartlett, John M. S.; Borgquist, Signe; Chang, Martin C.; Dodson, Andrew; Enos, Rebecca A.; Fineberg, Susan; Focke, Cornelia M.; Gao, Dongxia; Gown, Allen M.; Grabau, Dorthe; Gutierrez, Carolina; Hugh, Judith C.; Kos, Zuzana; Lænkholm, Anne-Vibeke; Lin, Ming-Gang; Mastropasqua, Mauro G.; Moriya, Takuya; Nofech-Mozes, Sharon; Osborne, C. Kent; Penault-Llorca, Frédérique M.; Piper, Tammy; Sakatani, Takashi; Salgado, Roberto; Starczynski, Jane; Viale, Giuseppe; Hayes, Daniel F.; McShane, Lisa M.; Dowsett, Mitch; Pathology and Laboratory Medicine, School of Medicine
    Pathological analysis of the nuclear proliferation biomarker Ki67 has multiple potential roles in breast and other cancers. However, clinical utility of the immunohistochemical (IHC) assay for Ki67 immunohistochemistry has been hampered by unacceptable between-laboratory analytical variability. The International Ki67 Working Group has conducted a series of studies aiming to decrease this variability and improve the evaluation of Ki67. This study tries to assess whether acceptable performance can be achieved on prestained core-cut biopsies using a standardized scoring method. Sections from 30 primary ER+ breast cancer core biopsies were centrally stained for Ki67 and circulated among 22 laboratories in 11 countries. Each laboratory scored Ki67 using three methods: (1) global (4 fields of 100 cells each); (2) weighted global (same as global but weighted by estimated percentages of total area); and (3) hot-spot (single field of 500 cells). The intraclass correlation coefficient (ICC), a measure of interlaboratory agreement, for the unweighted global method (0.87; 95% credible interval (CI): 0.81–0.93) met the prespecified success criterion for scoring reproducibility, whereas that for the weighted global (0.87; 95% CI: 0.7999–0.93) and hot-spot methods (0.84; 95% CI: 0.77–0.92) marginally failed to do so. The unweighted global assessment of Ki67 IHC analysis on core biopsies met the prespecified criterion of success for scoring reproducibility. A few cases still showed large scoring discrepancies. Establishment of external quality assessment schemes is likely to improve the agreement between laboratories further. Additional evaluations are needed to assess staining variability and clinical validity in appropriate cohorts of samples.
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    Inhibition of MEK signaling prevents SARS-CoV2-induced lung damage and improves the survival of infected mice
    (Wiley, 2022-08-28) Xie, Jingwu; Klemsz, Michael J.; Kacena, Melissa A.; Sandusky, George; Zhang, Xiaoli; Kaplan, Mark H.; Pathology and Laboratory Medicine, School of Medicine
    Coronavirus disease 2019 (COVID-19) is the illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Over 500 million confirmed cases of COVID-19 have been recorded, with 6 million deaths. Thus, reducing the COVID-19-related medical burden is an unmet need. Despite a vaccine that is successful in preventing COVID-19-caused death, effective medication to relieve COVID-19-associated symptoms and alleviate disease progression is still in high demand. In particular, one in three COVID-19 patients have signs of long COVID syndrome and are termed long haulers. At present, there are no effective ways to treat long haulers. In this study, we determine the effectiveness of inhibiting mitogen-activated protein kinase (MEK) signaling in preventing SARS-CoV-2-induced lung damage in mice. We showed that phosphorylation of extracellular signal-regulated kinase (ERK), a marker for MEK activation, is high in SARS-CoV-2-infected lung tissues of mice and humans. We show that selumetinib, a specific inhibitor of the upstream MEK kinases, reduces cell proliferation, reduces lung damage following SARS-CoV-2 infection, and prolongs the survival of the infected mice. Selumetinib has been approved by the US Food and Drug Administration (FDA) to treat cancer. Further analysis indicates that amphiregulin (AREG), an essential upstream molecule, was upregulated following SARS-CoV-2 infection. Our data suggest that MEK signaling activation represents a target for therapeutic intervention strategies against SARS-CoV-2-induced lung damage and that selumetinib may be repurposed to treat COVID-19.