NADH-Cytochrome b5 Reductase 3 Promotes Colonization and Metastasis Formation and Is a Prognostic Marker of Disease-Free and Overall Survival in Estrogen Receptor-Negative Breast Cancer

Metastasis is the main cause of cancer-related deaths and remains the most significant challenge to management of the disease. Metastases are established through a complex multistep process involving intracellular signaling pathways. To gain insight to proteins central to specific steps in metastasis formation, we used a metastasis cell line model that allows investigation of extravasation and colonization of circulating cancer cells to lungs in mice. Using stable isotopic labeling by amino acids in cell culture and subcellular fractionation, the nuclear, cytosol, and mitochondria proteomes were analyzed by LC-MS/MS, identifying a number of proteins that exhibited altered expression in isogenic metastatic versus nonmetastatic cancer cell lines, including NADH-cytochrome b5 reductase 3 (CYB5R3), l-lactate dehydrogenase A (LDHA), Niemann-pick c1 protein (NPC1), and nucleolar RNA helicase 2 (NRH2). The altered expression levels were validated at the protein and transcriptional levels, and analysis of breast cancer biopsies from two cohorts of patients demonstrated a significant correlation between high CYB5R3 expression and poor disease-free and overall survival in patients with estrogen receptor-negative tumors (DFS: p = .02, OS: p = .04). CYB5R3 gene knock-down using siRNA in metastasizing cells led to significantly decreased tumor burden in lungs when injected intravenously in immunodeficient mice. The cellular effects of CYB5R3 knock-down showed signaling alterations associated with extravasation, TGFβ and HIFα pathways, and apoptosis. The decreased apoptosis of CYB5R3 knock-down metastatic cancer cell lines was confirmed in functional assays. Our study reveals a central role of CYB5R3 in extravasation/colonization of cancer cells and demonstrates the ability of our quantitative, comparative proteomic approach to identify key proteins of specific important biological processes that may also prove useful as potential biomarkers of clinical relevance. MS data are available via ProteomeXchange with identifier PXD001391

Are Nonalcoholic Fatty Liver Disease and Bone Mineral Density Associated? — A Cross‐Sectional Study Using Liver Biopsy and Dual‐Energy X‐Ray Absorptiometry

ABSTRACT There is controversy regarding the association between nonalcoholic fatty liver disease (NAFLD) and osteoporosis. Our study aim was to assess bone mineral density (BMD) in patients with biopsy‐proven NAFLD and examine if the severity of NAFLD affects BMD. A total of 147 adult women (n = 108) and men (n = 39) aged 18–76 years (mean ± standard deviation [SD] age 45.3 ± 12.5) were recruited in this cross‐sectional study and underwent a liver biopsy and dual‐energy X‐ray absorptiometry (DXA). NAFLD activity score (NAS) based on the degree of steatosis, lobular inflammation and hepatocellular ballooning was used to assess NAFLD severity. The majority of subjects, 53%, had steatosis, 25% had nonalcoholic steatohepatitis (NASH) whereas 23% served as control subjects with no evidence of NAFLD. There were no significant differences in the lumbar spine (1.09 ± 0.12, 1.11 ± 0.18, and 1.12 ± 0.15 g/cm2, p = 0.69, in controls, steatosis, and NASH, respectively) or hip BMD (1.10 ± 0.15, 1.12 ± 0.13, and 1.09 ± 0.13 g/cm2, p = 0.48, in controls, steatosis, and NASH, respectively) between the groups. Adjusting for age, gender, body mass index, and diabetes in multiple regression models did not alter the results. There was no correlation between NAS and neither lumbar spine BMD (r = 0.06, p = 0.471), nor hip BMD (r = −0.03, p = 0.716). In conclusion, BMD was similar across the spectrum of NAFLD in both genders and not related to the severity of the underlying histological lesions, suggesting that neither steatosis nor NASH exerts a detrimental effect on BMD in these relatively young patients. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research

Standardized assessment of tumor-infiltrating lymphocytes in breast cancer: an evaluation of inter-observer agreement between pathologists

<p><b>Introduction:</b> In breast cancer, there is a growing body of evidence that tumor-infiltrating lymphocytes (TILs) may have clinical utility and may be able to direct clinical decisions for subgroups of patients. Clinical utility is, however, not sufficient for warranting the implementation of a new biomarker in the routine practice, and evaluation of the analytical validity is needed, including testing the reproducibility of decentralized assessment of TILs. The aim of this study was to evaluate the inter-observer agreement of TILs assessment using a standardized method, as proposed by the International TILs Working Group 2014, applied to a cohort of breast cancers reflecting an average breast cancer population.</p> <p><b>Material and methods:</b> Stromal TILs were assessed using full slide sections from 124 breast cancers with varying histology, malignancy grade and ER- and HER2 status. TILs were estimated by nine dedicated breast pathologists using scanned hematoxylin–eosin stainings. TILs results were categorized using various cutoffs, and the inter-observer agreement was evaluated using the intraclass coefficient (ICC), Kappa statistics as well as individual overall agreements with the median value of TILs.</p> <p><b>Results:</b> Evaluation of TILs led to an ICC of 0.71 (95% CI: 0.65–0.77) corresponding to an acceptable agreement. Kappa values were in the range of 0.38–0.46 corresponding to a fair to moderate agreement. The individual agreements increased, when using only two categories (‘high’ vs. ‘low’ TILs) and a cutoff of 50–60%.</p> <p><b>Discussion:</b> The results of the present study are in accordance with previous studies, and shows that the proposed methodology for standardized evaluation of TILs renders an acceptable inter-observer agreement. The findings, however, indicate that assessment of TILs needs further refinement, and is in support of the latest St. Gallen Consensus, that routine reporting of TILs for early breast cancer is not ready for implementation in a clinical setting.</p

An inter-observer Ki67 reproducibility study applying two different assessment methods:on behalf of the Danish Scientific Committee of Pathology, Danish breast cancer cooperative group (DBCG)

Introduction: In 2011, the St. Gallen Consensus Conference introduced the use of pathology to define the intrinsic breast cancer subtypes by application of immunohistochemical (IHC) surrogate markers ER, PR, HER2 and Ki67 with a specified Ki67 cutoff (>14%) for luminal B-like definition. Reports concerning impaired reproducibility of Ki67 estimation and threshold inconsistency led to the initiation of this quality assurance study (2013–2015). The aim of the study was to investigate inter-observer variation for Ki67 estimation in malignant breast tumors by two different quantification methods (assessment method and count method) including measure of agreement between methods. Material and methods: Fourteen experienced breast pathologists from 12 pathology departments evaluated 118 slides from a consecutive series of malignant breast tumors. The staining interpretation was performed according to both the Danish and Swedish guidelines. Reproducibility was quantified by intra-class correlation coefficient (ICC) and Lights Kappa with dichotomization of observations at the larger than (>) 20% threshold. The agreement between observations by the two quantification methods was evaluated by Bland–Altman plot. Results: For the fourteen raters the median ranged from 20% to 40% by the assessment method and from 22.5% to 36.5% by the count method. Light’s Kappa was 0.664 for observation by the assessment method and 0.649 by the count method. The ICC was 0.82 (95% CI: 0.77–0.86) by the assessment method vs. 0.84 (95% CI: 0.80–0.87) by the count method. Conclusion: Although the study in general showed a moderate to good inter-observer agreement according to both ICC and Lights Kappa, still major discrepancies were identified in especially the mid-range of observations. Consequently, for now Ki67 estimation is not implemented in the DBCG treatment algorithm