RGS5+ lymphatic endothelial cells facilitate metastasis and acquired drug resistance of breast cancer through oxidative stress-sensing mechanism.

AIMS: Oxidative stress reflected by elevated reactive oxygen species (ROS) in the tumor ecosystem, is a hallmark of human cancers. The mechanisms by which oxidative stress regulate the metastatic ecosystem and resistance remain elusive. This study aimed to dissect the oxidative stress-sensing machinery during the evolvement of early dissemination and acquired drug resistance in breast cancer. METHODS: Here, we constructed single-cell landscape of primary breast tumors and metastatic lymph nodes, and focused on RGS5+ endothelial cell subpopulation in breast cancer metastasis and resistance. RESULTS: We reported on RGS5 as a master in endothelial cells sensing oxidative stress. RGS5+ endothelial cells facilitated tumor-endothelial adhesion and transendothelial migration of breast cancer cells. Antioxidant suppressed oxidative stress-induced RGS5 expression in endothelial cells, and prevented adhesion and transendothelial migration of cancer cells. RGS5-overexpressed HLECs displayed attenuated glycolysis and oxidative phosphorylation. Drug-resistant HLECs with RGS5 overexpression conferred acquired drug resistance of breast cancer cells. Importantly, genetic knockdown of RGS5 prevented tumor growth and lymph node metastasis. CONCLUSIONS: Our work demonstrates that RGS5 in lymphatic endothelial cells senses oxidative stress to promote breast cancer lymph node metastasis and resistance, providing a novel insight into a potentially targetable oxidative stress-sensing machinery in breast cancer treatment.

Acquisition Efficiency and Technical Repeatability of Dual-Frequency 3D Vector MR Elastography of the Liver.

BACKGROUND: MR elastography (MRE) at 60 Hz is widely used for staging liver fibrosis. MRE with lower frequencies may provide inflammation biomarkers. PURPOSE: To establish a practical simultaneous dual-frequency liver MRE protocol at both 30 Hz and 60 Hz during a single examination and validate the occurrence of second harmonic waves at 30 Hz. STUDY TYPE: Retrospective. SUBJECTS: One hundred six patients (48 females, age: 50.0 ± 13.4 years) were divided as follows: Cohort One (15 patients with chronic liver disease [CLD] and 25 healthy volunteers) with simultaneous dual-frequency MRE. Cohort Two (66 patients with CLD) with second harmonic MRE. FIELD STRENGTH/SEQUENCE: 3-T, single- or dual-frequency MRE at 30 Hz and 60 Hz. ASSESSMENT: Liver stiffness (LS) in both cohorts was evaluated with manually placed volumetric ROIs by two independent analyzers. Image quality was assessed by three independent readers on a 4-point scale (0-3: none/failed, fair, moderate, excellent) based on the depth of wave propagation with 1/3 incremental penetration. The success rate was derived from the percentage of nonzero quality scores. STATISTICAL TESTS: Measurement agreement, bias, and repeatability of LS were assessed using intraclass correlation coefficients (ICCs), Bland-Altman plots, and repeatability coefficient (RC). Mann-Whitney U tests were used to evaluate the differences in image quality between different methods. A P-value <0.05 was considered statistically significant. RESULTS: Success rate was 97.5% in Cohort One and 91% success rate for the second harmonic MRE in Cohort Two. The second harmonic and conventional MRE showed excellent agreement in LS (all ICCs >0.90). The quality scores for the second harmonic wave images were lower than those from the conventional MRE (Z = -4.523). DATA CONCLUSION: Compared with conventional and second harmonic methods, simultaneous dual-frequency had better image quality, high success rate and the advantage of intrinsic co-registration, while the second harmonic method can be an alternative if custom waveform is not available. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 1.

Evaluation of Kidney Injury Using Arterial Spin Labeling and Blood Oxygen Level-Dependent MRI: An Experimental Study in Rats With Carbon Tetrachloride-Induced Liver Cirrhosis.

BACKGROUND: Serum creatinine (Scr) may be not suited to timely and accurately reflect kidney injury related to chronic liver disease. Currently, the ability of arterial spin labeling (ASL) and blood oxygen level-dependent (BOLD) sequences to evaluate renal blood flow (RBF) and blood oxygen in chronic liver disease remains to be verified. PURPOSE: To investigate the value of ASL and BOLD imaging in evaluating hemodynamics and oxygenation changes during kidney injury in an animal model of chronic liver disease. STUDY TYPE: Prospective. ANIMAL MODEL: Chronic liver disease model was established by subcutaneous injection of carbon tetrachloride. Forty-three male Sprague-Dawley rats (8 weeks) were divided into a pathological group (0, 2, 4, 6, 8, 12 weeks, each group: N = 6) and a continuous-scanning group (N = 7). FIELD STRENGTH/SEQUENCE: 3-T, ASL, BOLD, and T2W. ASSESSMENT: Regions of interest in the cortex (CO), outer stripe of the outer medulla (OSOM), and inner stripe of the outer medulla (ISOM) are manually delineated. The RBF and T2* values at each time point (0, 2, 4, 6, 8, 12 weeks) are measured and compared. Hematoxylin-eosin score (HE Score, damage area scoring method), alpha-smooth muscle actin (α-SMA), hypoxia-inducible factor-1alpha (HIF-1α), peritubular capillar (PTC) density, Scr, and neutrophil gelatinase-associated lipocalin were harvested. STATISTICAL TESTS: Analysis of variance, Spearman correlation analysis, Kruskal-Wallis tests, and receiver operating characteristic analysis with the area under the curve (AUC). A P-value <0.05 was considered statistically significant. RESULTS: Renal RBF and T2* values of CO, OSOM, and ISOM were significantly different from baseline. Both RBF and T2* were significantly correlated with HE Score, α-SMA, HIF-1α, and PTC density (|r| = 0.406-0.853). RBF demonstrated superior diagnostic capability in identifying severe kidney injury in this model of chronic liver disease (AUC = 0.964). DATA CONCLUSION: Imaging by ASL and BOLD may detect renal hemodynamics and oxygenation changes related to chronic liver disease early. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 2.

Perfusion Analysis of Kidney Injury in Rats With Cirrhosis Induced by Common Bile Duct Ligation Using Arterial Spin Labeling MRI.

BACKGROUND: Arterial spin labeling (ASL) has been proven to be effective in ischemia-induced acute kidney injury (AKI); however, validation of ASL magnetic resonance imaging (MRI) is limited in AKI in the presence of cirrhosis. PURPOSE: To investigate the feasibility of ASL in revealing renal blood flow (RBF) changes in kidney injury in the presence of cirrhosis and to assess its value in the early diagnosis of disease. STUDY TYPE: Longitudinal. ANIMAL MODEL: Rats were randomized into baseline group (N = 3), sham surgery group (N = 18), and common bile duct ligation (BDL) group (N = 48). All groups were divided into six subgroups based on different sacrificed time points. FIELD STRENGTH/SEQUENCE: 3 T scanner, prototypic pulsed ASL sequence using flow-sensitive alternating inversion recovery preparation, half-Fourier acquisition single-shot turbo spin echo sequence. ASSESSMENT: RBF measurement was performed by ASL. Hematoxylin-eosin (HE) score, Hypoxia-inducible factor-1alpha (HIF-1α) score, peritubular capillar (PTC) density, alanine aminotransferase, aspartate aminotransferase, serum total bilirubin, total bile acids, serum creatinine (Scr), and blood urea nitrogen (BUN) were harvested. STATISTICAL TESTS: Analysis of variance, Pearson's correlation coefficient, and receiver operating characteristic curves were performed. P < 0.05 was considered statistically significant. RESULTS: RBF, HE score, HIF-1α score, and PTC density after BDL were significantly different from baseline. RBF was highly correlated with HE score, HIF-1α score, and PTC density (r = -0.7598, r = -0.7434, r = 0.6406, respectively). RBF and Scr began to differ significantly from baseline at day 3 and 7 after intervention, respectively. The areas under the curves of RBF, Scr, and BUN for distinguishing non-AKI from AKI in cirrhosis were 1.00, 0.888, and 0.911, while those for distinguishing mild from severe kidney injury were 0.961, 0.830, and 0.857, respectively. DATA CONCLUSION: ASL allows the longitudinal assessment of the degree of AKI induced by cholestatic cirrhosis in rats and can serve as a noninvasive marker for the early and accurate diagnosis of AKI. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.

Multi-parametric magnetic resonance imaging of liver regeneration in a standardized partial hepatectomy rat model.

BACKGROUND: We aimed to evaluate the correlation between the pathological changes and multi-parameter MRI characteristics of liver regeneration (LR) in a standard partial hepatectomy (PH) rat model. METHODS: Seventy Sprague-Dawley rats were randomly divided into two groups: MR scan group (n = 14) and pathologic analysis (PA) group (n = 56). All 14 rats in the MR group underwent liver T1 mapping, T2 mapping, and diffusion kurtosis imaging before and the 1st, 2nd, 3rd, 5th, 7th, 14th, and 21st day after 70% hepatectomy. Seven rats in the PA group were euthanized at each time point to determine Ki-67 indices, hepatocyte size (HTS), steatosis grade, and inflammation score. RESULTS: Liver T1 and T2 values increased to maximum on day 2 (P < 0.001 vs. baseline), D and K values decreased to minimum on day 3 and 2, respectively (P < 0.001 vs. baseline), then all parameters returned to baseline gradually. Hepatocyte Ki-67, hepatocyte size, steatosis grade, and inflammation score initially increased after surgery (P < 0.05 vs. baseline), followed by a gradual decline over time. Both T2 and K values correlated well with Ki-67 indices (r = 0.765 and - 0.807, respectively; both P < 0.001), inflammation (r = 0.809 and - 0.724, respectively; both P < 0.001), steatosis grade (r = 0.814 and - 0.725, respectively; both P < 0.001), and HTS (r = 0.830 and - 0.615, respectively; both P < 0.001). CONCLUSIONS: PH induced liver changes that can be observed on MRI. The MRI parameters correlate with the LR activity and allow monitoring of LR process.

Can negative axillary ultrasound reliably predict pathologically negative axillary lymph node status in breast cancer patients with cT ≤3 cm, cN0, and HER2-positive?-a retrospective, single-institution study.

Background: Breast cancer (BC) is the leading cancer in women globally, with human epidermal growth factor receptor 2 (HER2)-positive subtype accounting for 15-20% of cases and exhibiting aggressive behavior. The standard of care for operable BC has evolved to include neoadjuvant systemic therapy, which can guide treatment decisions and improve outcomes, particularly in HER2+ BC. This study aims to investigate whether axillary ultrasound has a good negative predictive value (NPV) for early HER2 BC patients and to identify clinicopathological factors that can impact the axillary lymph node metastasis. Methods: This retrospective, single-center study evaluated the medical records of 135 patients with HER2+ BC, cT ≤3 cm, and clinically negative axillary lymph nodes from 2018 to 2020. The study aimed to determine the NPV of axillary ultrasound for pathologically negative axillary lymph node status and to identify factors associated with axillary lymph node metastasis. Results: The NPV of axillary ultrasound was 78.5%, increasing to 89.6% and 93.3% when considering 0-1 and 0-2 metastatic lymph nodes, respectively. Lymphovascular invasion (LVI) was significantly associated with axillary lymph node metastasis, with a 2.2-fold increased risk. Conclusions: Axillary ultrasound shows good predictive value for axillary lymph node negativity in HER2+ BC patients with small tumors. However, the presence of LVI increases the risk of metastasis, suggesting a need for neoadjuvant chemotherapy. These findings contribute to personalized treatment strategies for early HER2+ BC, emphasizing the role of axillary ultrasound in clinical decision-making.

Central lymph node ratio is an important recurrence prognostic factor for pediatric differentiated thyroid cancer.

Background: The current risk stratification methods for Pediatric Differentiated Thyroid Carcinoma (DTC) are deemed inadequate due to the high recurrence rates observed in this demographic. This study investigates alternative clinicopathological factors, specifically the Central Lymph Node Ratio (CLNR), for improved risk stratification in pediatric DTC. Methods: A retrospective review of 100 pediatric DTC patients, aged 19 or younger, treated between December 2012 and January 2021 at the First Affiliated Hospital of Guangxi Medical University was conducted. Clinicopathological variables were extracted, and univariate logistic regression identified factors correlated with recurrence. Kaplan-Meier (KM) survival analysis and subsequent statistical tests were used to assess the significance of these factors. Results: The CLNR, with a cutoff value of 77.78%, emerged as a significant predictor of recurrence. Patients with a CLNR above this threshold had a 5.467 times higher risk of recurrence. The high CLNR group showed a higher proportion of male patients, clinically lymph node positivity (cN1), and extrathyroidal extension (ETE) compared to the low-risk group (p<0.05). Conclusion: CLNR is a valuable predictor for recurrence in pediatric DTC and aids in stratifying patients based on Recurrence-Free Survival (RFS). For patients with a high CLNR, aggressive iodine-131 therapy, stringent TSH suppression, and proactive postoperative surveillance are recommended to mitigate recurrence risk and facilitate timely detection of recurrent lesions.

Use of Intravoxel Incoherent Motion Diffusion-Weighted Imaging to Assess Mesenchymal Stromal Cells Promoting Liver Regeneration in a Rat Model.

RATIONALE AND OBJECTIVES: Mesenchymal stem cells (MSCs) have the potential to promote liver regeneration, but the process is unclear. This study aims to explore the therapeutic effects and dynamic processes of MSCs in liver regeneration through intravoxel incoherent motion (IVIM) imaging. ANIMAL MODEL: 70 adult Sprague-Dawley rats were randomly divided into either the control or MSC group (n = 35/group). All rats received a partial hepatectomy (PH) with the left lateral and middle lobes removed. Each group was divided into seven subgroups: pre-PH and 1, 2, 3, 5, 7, and 14 days post-PH (n = 5 rats/subgroup). Magnetic resonance imaging (MRI) was performed before obtaining pathological specimens at each time point on postoperative days 1, 2, 3, 5, 7, and 14. The MRI parameters for the pure diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (PF) were calculated. Correlation analysis was conducted for the biochemical markers (alanine transaminase [ALT], aspartate transaminase [AST], and total bilirubin [TBIL]), histopathological findings (hepatocyte size and Ki-67 proliferation index), liver volume (LV) and liver regeneration rate (LLR). RESULTS: Liver D, D* , and PF differed significantly between the control and MSC groups at all time points (all P < 0.05). After PH, the D increased, then decreased, and the D* and PF decreased, then increased in both groups. The hepatocyte Ki-67 proliferation index of the MSC group was lower on day 2 post-PH, but higher on days 3 and 5 post-PH than that of the control group. Starting from day 3 post-PH, both the LV and LLR in the MSC group were greater than those in the control group (all P < 0.05). Hepatocytes were larger in the MSC group than in the control group on days 2 and 7 post-PH. In the MSC group, the D, D* , and PF were correlated with the AST levels, Ki-67 index and hepatocyte size (|r|=0.35-0.71; P < 0.05). In the control group, the D and D* were correlated with ALT levels, AST levels, Ki-67 index, LLR, LV, and hepatocyte size (|r|=0.34-0.95; P < 0.05). CONCLUSION: Bone marrow MSC therapy can promote hepatocyte hypertrophy and prolong liver proliferation post-PH. IVIM parameters allow non-invasively evaluating the efficacy of MSCs in promoting LR.

T1 mapping combined with arterial spin labeling MRI to identify renal injury in patients with liver cirrhosis.

Purpose: We investigated the capability and imaging criteria of T1 mapping and arterial spin labeling (ASL) MRI to identify renal injury in patients with liver cirrhosis. Methods: We recruited 27 patients with cirrhosis and normal renal function (cirrhosis-NR), 10 with cirrhosis and renal dysfunction (cirrhosis-RD) and 23 normal controls (NCs). All participants were examined via renal T1 mapping and ASL imaging. Renal blood flow (RBF) derived from ASL was measured from the renal cortex, and T1 values were measured from the renal parenchyma (cortex and medulla). MRI parameters were compared between groups. Diagnostic performances for detecting renal impairment were statistically analyzed. Results: Cortical T1 (cT1) and medullary T1 (mT1) were significantly lower in the NCs than in the cirrhosis-NR group. The cortical RBF showed no significant changes between the NCs and cirrhosis-NR group but was markedly decreased in the cirrhosis-RD group. The areas under the curve (AUCs) for discriminating cirrhosis-NR from NCs were 0.883 and 0.826 by cT1 and mT1, respectively. Cortical RBF identified cirrhosis-RD with AUC of 0.978, and correlated with serum creatinine (r = -0.334) and the estimated glomerular filtration rate (r = 0.483). A classification and regression tree based on cortical RBF and cT1 achieved 85% accuracy in detecting renal impairment in the cirrhosis. Conclusion: Renal T1 values might be sensitive predictors of early renal impairment in patients with cirrhosis-NR. RBF enabled quantifying renal perfusion impairment in patients with cirrhosis-RD. The diagnostic algorithm based on cortical RBF and T1 values allowed detecting renal injury during cirrhosis.

Exploring the biological behavior and underlying mechanism of KITLG in triple-negative breast cancer.

The tyrosine-kinase receptor that is specified by the KIT locus is demarcated by KITLG. This multifaceted factor is instrumental during in-utero germ and neural cell maturation and hematopoiesis, ostensibly reflecting its role in facilitating cell migration. Concurrently, KITLG is prone to a mutation in germ cell tumors, entailing a presumed connection to tumorigenesis. Despite this, the intricacies of its function in breast cancer and the relevant mechanisms remain elusive. Multiple independent databases depict a consistently low expression of KITLG within tissues affected by triple-negative breast cancers (TNBC), a trend strongly coupled with reduced survival rates. Interestingly, non-triple-negative breast cancers exhibit a markedly high expression of KITLG compared to the norm. An initial analysis of the GEO database speculates that KITLG may serve as an oncogene suppressor in TNBC, hinting at varied roles for KITLG isoforms within this disease context. In conclusion, our preliminary analysis offers valuable insights into the role and expression pattern of KITLG in TNBC. We provide evidence supporting its consideration as a promising new prognostic marker, thereby potentially enriching therapeutic strategies for TNBC. Indeed, given the limited advances in molecularly targeted therapy for TNBC, a significant need exists for a more precise therapeutic approach and a comprehensive understanding of its inherent mechanisms of action.

Abdominal MR elastography with multiple driver arrays: performance and repeatability.

PURPOSE: To evaluate the performance and repeatability assessing liver, spleen, and kidney stiffness with magnetic resonance elastography (MRE), using arrays of pneumatic passive drivers. METHODS: An array of four flexible, pneumatically activated passive drivers for abdominal MRE were developed and tested in this study. Multiple MRE acquisitions were performed prospectively in a series of eleven volunteers, with activation of all combinations of the four drivers, individually and simultaneously. MRE exams were repeated three times to study within-day and between-day test-retest repeatability. Semi-quantitative evaluation of wave propagation and penetration, and quantitative assessment of tissue stiffness was conducted for liver, spleen, and kidneys. RESULTS: When driver location and amplitude were sufficient to achieve necessary shear wave illumination in any given region of interest, the results showed excellent test-retest repeatability in abdominal organ stiffness with both single and multiple driver configurations. The results confirmed that multiple driver arrays provided suitable shear wave illumination over a larger region of the abdomen, allowing more reliable stiffness measurements in multiple organs. MRE assessment of the spleen was found to be prone to effects of excessive shear wave amplitude, however. CONCLUSION: A multiple driver array provides shear wave illumination over a larger region of the abdomen than obtained with a single driver, for MRE assessment of multiple abdominal organs, providing excellent test-retest repeatability in stiffness measurements. However, careful tuning of the location and amplitude of each driver is essential to achieve consistent results.

Series of Intravoxel Incoherent Motion and T2* Magnetic Resonance Imaging Mapping in Detection of Liver Perfusion Changes and Regeneration Among Partial Hepatectomy in Sprague-Dawley Rats.

RATIONALE AND OBJECTIVES: To evaluate liver perfusion changes and their effect on liver regeneration (LR) after partial hepatectomy (PH) using intravoxel incoherent motion (IVIM) and T2* mapping in a rat model. METHODS: One hundred and two rats underwent 30%, 50%, or 70% PH. Within each group (n = 34), rats in MR imaging subgroup (n = 10) underwent liver IVIM and T2* mapping before and within 2 h, 1, 2, 3, 5, 7, 14, and 21 days post-PH to measure D*, perfusion fraction (PF), and T2* values. Three rats from histologic subgroup (n = 24) sacrificed at each time point for hepatocyte Ki-67 indices and diameters measurement. RESULTS: Liver D* and PF values decreased immediately post-PH, then returned to original level as LR progressed in all groups. PF values in 70% PH group were significantly lower than in the other two groups (p < .05). D* and PF values correlated significantly with hepatocyte Ki-67 indices (r = -0.588 to -0.915; p < .05) and hepatocyte diameter (r = -0.555 to -0.792; p < .05). Liver T2* values decreased immediately within 2 h post-PH, then increased to a high level and followed with returning to original level gradually. The duration of the high T2* levels was consistent with Ki-67 indices. CONCLUSIONS: Liver perfusion decreased immediately followed with increasing gradually after PH. IVIM and T2* mapping are promising methods for monitoring changes of liver perfusion. IVIM-derived D* value is the best indicator in reflecting the process of LR noninvasively.

Assessment of Fibrotic Liver Regeneration After Partial Hepatectomy With Intravoxel Incoherent Motion Diffusion-Weighted Imaging: An Experimental Study in a Rat Model With Carbon Tetrachloride Induced Liver Injury.

PURPOSE: To determine whether intravoxel incoherent motion (IVIM) parameters correlate with liver regeneration and function recovery after partial hepatectomy (PH) in rats with carbon tetrachloride (CCl4)-induced liver fibrosis. METHODS: Sixty-two adult Sprague-Dawley rats were divided into the control group and the fibrosis group with CCl4 injection for 8 weeks. At the end of the 8th week, all rats received left lateral lobe liver resection. Within each group, IVIM imaging (n = 10/group) and histologic and biochemical analyses (n = 3/group/time point) were performed pre- and post-PH (on days 1, 2, 3, 5, 7, 14, and 21). Differences in liver IVIM parameters and correlation between IVIM parameters and Ki-67 indices, hepatocyte diameter, alanine transaminase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBil) values were analyzed. RESULTS: Post-PH, liver true diffusion coefficient (D) values decreased and pseudodiffusion coefficient (D*) and perfusion fraction (PF) values increased, then recovered to pre-PH levels gradually in both fibrosis and control rats. PF in fibrosis group were significantly higher than in controls from 3 to 21 days (P < 0.05). In fibrosis rats, both Ki-67 indices and hepatocyte diameters increased, and a strong correlation was found between PF and Ki-67 indices (r = -0.756; P = 0.03), D* and PF values and ALT, AST, and TBil values (r = -0.762 to -0.905; P < 0.05). In control rats, only hepatocyte diameters increased, and all IVIM parameters correlated well with hepatocyte diameters, ALT, AST and TBil values (r = 0.810 to -1.000; P < 0.05). CONCLUSION: The regeneration pattern in fibrotic liver tissue was different compared with control livers. IVIM parameters can monitor liver regeneration and functional recovery non-invasively after PH.