Development and Validation of MRI Radiomics Models to Differentiate HER2-Zero, -Low, and -Positive Breast Cancer.

BACKGROUND. Breast cancer HER2 expression has been redefined using a three-tiered system, with HER2-zero cancers considered ineligible for HER2-targeted therapy, HER2-low cancers considered candidates for novel HER2-targeted drugs, and HER2-positive cancers treated with traditional HER2-targeted medications. OBJECTIVE. The purpose of this study was to assess MRI radiomics models for a three-tiered classification of HER2 expression of breast cancer. METHODS. This retrospective study included 592 patients with pathologically confirmed breast cancer (mean age, 47.0 ± 18.0 [SD] years) who underwent breast MRI at either of a health system's two hospitals from April 2016 through June 2022. Three-tiered HER2 status was pathologically determined. Radiologists assessed the conventional MRI features of tumors and manually segmented the tumors on multiparametric sequences (T2-weighted images, DWI, ADC maps, and T1-weighted delayed contrast-enhanced images) to extract radiomics features. Least absolute shrinkage and selection operator analysis was used to develop two radiomics signatures, to differentiate HER2-zero cancers from HER2-low or HER2-positive cancers (task 1) as well as to differentiate HER2-low cancers from HER2-positive cancers (task 2). Patients from hospital 1 were randomly assigned to a discovery set (task 1: n = 376; task 2: n = 335) or an internal validation set (task 1: n = 161; task 2: n = 143); patients from hospital 2 formed an external validation set (task 1: n = 55; task 2: n = 50). Multivariable logistic regression analysis was used to create nomograms combining radiomics signatures with clinicopathologic and conventional MRI features. RESULTS. AUC, sensitivity, and specificity in the discovery, internal validation, and external validation sets were as follows: for task 1, 0.89, 99.4%, and 69.0%; 0.86, 98.6%, and 76.5%; and 0.78, 100.0%, and 0.0%, respectively; for task 2, 0.77, 93.8%, and 32.3%; 0.75, 92.9%, and 6.8%; and 0.77, 97.0%, and 29.4%, respectively. For task 1, no nomogram was created because no clinicopathologic or conventional MRI feature was associated with HER2 status independent of the MRI radiomics signature. For task 2, a nomogram including an MRI radiomics signature and three pathologic features (histologic grade of III, high Ki-67 index, and positive progesterone receptor status) that were independently associated with HER2-low expression had an AUC of 0.87, 0.83, and 0.80 in the three sets. CONCLUSION. MRI radiomics features were used to differentiate HER2-zero from HER2-low cancers or HER2-positives cancers as well as to differentiate HER2-low cancers from HER2-positive cancers. CLINICAL IMPACT. MRI radiomics may help select patients for novel or traditional HER2-targeted therapies, particularly those patients with ambiguous results of immunohistochemical staining results or limited access to fluorescence in situ hybridization.

CXCL10 and Nrf2-upregulated mesenchymal stem cells reinvigorate T lymphocytes for combating glioblastoma.

BACKGROUND: Lack of tumor-infiltrating T lymphocytes and concurrent T-cell dysfunction have been identified as major contributors to glioblastoma (GBM) immunotherapy resistance. Upregulating CXCL10 in the tumor microenvironment (TME) is a promising immunotherapeutic approach that potentially increases tumor-infiltrating T cells and boosts T-cell activity but is lacking effective delivery methods. METHODS: In this study, mesenchymal stem cells (MSCs) were transduced with a recombinant lentivirus encoding Cxcl10, Nrf2 (an anti-apoptosis gene), and a ferritin heavy chain (Fth) reporter gene in order to increase their CXCL10 secretion, TME survival, and MRI visibility. Using FTH-MRI guidance, these cells were injected into the tumor periphery of orthotopic GL261 and CT2A GBMs in mice. Combination therapy consisting of CXCL10-Nrf2-FTH-MSC transplantation together with immune checkpoint blockade (ICB) was also performed for CT2A GBMs. Thereafter, in vivo and serial MRI, survival analysis, and histology examinations were conducted to assess the treatments' efficacy and mechanism. RESULTS: CXCL10-Nrf2-FTH-MSCs exhibit enhanced T lymphocyte recruitment, oxidative stress tolerance, and iron accumulation. Under in vivo FTH-MRI guidance and monitoring, peritumoral transplantation of CXCL10-Nrf2-FTH-MSCs remarkably inhibited orthotopic GL261 and CT2A tumor growth in C57BL6 mice and prolonged animal survival. While ICB alone demonstrated no therapeutic impact, CXCL10-Nrf2-FTH-MSC transplantation combined with ICB demonstrated an enhanced anticancer effect for CT2A GBMs compared with transplanting it alone. Histology revealed that peritumorally injected CXCL10-Nrf2-FTH-MSCs survived longer in the TME, increased CXCL10 production, and ultimately remodeled the TME by increasing CD8+ T cells, interferon-γ+ cytotoxic T lymphocytes (CTLs), GzmB+ CTLs, and Th1 cells while reducing regulatory T cells (Tregs), exhausted CD8+ and exhausted CD4+ T cells. CONCLUSIONS: MRI-guided peritumoral administration of CXCL10 and Nrf2-overexpressed MSCs can significantly limit GBM growth by revitalizing T lymphocytes within TME. The combination application of CXCL10-Nrf2-FTH-MSC transplantation and ICB therapy presents a potentially effective approach to treating GBM.