Vinamratha Rao

With over 60,000 cases diagnosed annually in the US, ductal carcinoma in situ (DCIS) is the most prevalent form of early-stage breast cancer. Because many DCIS cases never progress to invasive ductal carcinomas (IDC), overtreatment remains a significant problem. Up to 20% patients experience disease recurrence, indicating that standard treatments do not effectively treat DCIS for a subset of patients. By understanding the mechanisms of DCIS progression, we can develop new treatment strategies better tailored to patients. The chemokine CCL2 and its receptor CCR2 are known to regulate macrophage recruitment during inflammation and cancer progression. Recent studies indicate that increased CCL2/CCR2 signaling in breast epithelial cells enhance formation of IDC. Here, we characterized the molecular mechanisms important for CCL2/CCR2-mediated DCIS progression. Phospho-protein array profiling revealed that CCL2 stimulated phosphorylation of MET receptor tyrosine kinases in breast cancer cells. Co-immunoprecipitation and proximity ligation assays demonstrated that CCL2-induced MET activity depended on interactions with CCR2 and SRC. Extracellular flux analysis and biochemical assays revealed that CCL2/CCR2 signaling in breast cancer cells enhanced glycolytic enzyme expression and activity. CRISPR knockout and pharmacologic inhibition of MET revealed that CCL2/CCR2-induced breast cancer cell proliferation, survival, migration and glycolysis through MET-dependent mechanisms. In animals, MET inhibitors blocked CCR2-mediated DCIS progression and metabolism. CCR2 and MET were significantly co-expressed in patient DCIS and IDC tissues. In summary, MET receptor activity is an important mechanism for CCL2/CCR2-mediated progression and metabolism of early-stage breast cancer, with important clinical implications.

Background/Introduction: (DCIS) affects over 50,000 women in the US annually. Despite standardized treatment involving lumpectomy and radiation therapy, up to 25% of patients with DCIS experience disease recurrence often with invasive ductal carcinoma (IDC), indicating that a subset of patients may be under-treated. As most DCIS cases will not progress to invasion, many patients may experience over-treatment. By understanding the underlying processes associated with DCIS to IDC progression, we can identify new biomarkers to determine which DCIS cases may become invasive and improve treatment for patients. Accumulation of fibroblasts in IDC is associated with disease progression and reduced survival. While fibroblasts have been detected in DCIS, little is understood about their role in DCIS progression. Goals: We sought to determine 1) whether DCIS fibroblasts were similar or distinct from normal and IDC fibroblasts at the transcriptome level, and 2) the contributions of DCIS fibroblasts to breast cancer progression. Methods: Fibroblasts underwent transcriptome profiling and pathway analysis. Significant DCIS fibroblast-associated genes were further analyzed in existing breast cancer mRNA databases and through tissue array immunostaining. Using the sub-renal capsule graft model, fibroblasts from normal breast, DCIS and IDC tissues were co-transplanted with DCIS.com breast cancer cells. Results: Through transcriptome profiling, we found that DCIS fibroblasts were characterized by unique alterations in cell cycle and motility related genes such as PKMYT1, TGF-α, SFRP1 and SFRP2, which predicted increased cell growth and invasion by Ingenuity Pathway Analysis. Immunostaining analysis revealed corresponding increases in expression of stromal derived PKMYT1, TGF-α and corresponding decreases in expression of SFRP1 and SFRP2 in DCIS and IDC tissues. Grafting studies in mice revealed that DCIS fibroblasts enhanced breast cancer growth and invasion associated with arginase-1+ cell recruitment. Conclusion: DCIS fibroblasts are phenotypically distinct from normal breast and IDC fibroblasts, and play an important role in breast cancer growth, invasion, and recruitment of myeloid cells. These studies provide novel insight into the role of DCIS fibroblasts in breast cancer progression and identify some key biomarkers associated with DCIS progression to IDC, with important clinical implications.

Key Points Twenty-seven percent of patients with autosomal dominant polycystic kidney disease discontinued tolvaptan in a real-world cohort in the midwestern United States. Most patients maintained tolvaptan on lower doses than trials, and a minority tolerated above the 45 mg ( am )/15 mg ( pm ) starting dosage. Adverse effects, specifically aquaretic side effects, strongly influenced tolvaptan tolerability, dosage titration, and discontinuation. Background Autosomal dominant polycystic kidney disease (ADPKD) is the most prevalent genetic kidney disease leading to kidney failure. Tolvaptan, a vasopressin V2 receptor antagonist, is the only medication approved by the US Food and Drug Administration for slowing kidney growth in individuals with rapidly progressive ADPKD, but its long-term tolerability and effective implementation has yet to be studied, particularly in real-world clinical settings within the United States. Methods This retrospective cohort study examined adults with ADPKD treated with tolvaptan at the University of Kansas Medical Center and the University of Iowa Hospitals & Clinics from May 2018 to April 2023. Data on demographics, clinical characteristics, tolvaptan dosage, and treatment duration were collected from electronic health records for an average follow-up duration of 28.2 months (interquartile range: 8.5–47.1 months). The study focused on examining tolvaptan dosage trends, treatment discontinuation reasons, and the impact of aquaretic side effects on dosage and adherence. Results Of 134 patients, 27% stopped tolvaptan during the observational period, with 10.4% of the cohort withdrawing from treatment due to intolerance of aquaretic side effects. Most patients maintained a lower tolvaptan dosage (≤45/15 mg) than in clinical trials, with two thirds of individuals who underwent dosage adjustment undergoing net decrease in dosage. Adverse effects significantly influenced and dosage decisions, presenting a potential early barrier for adherence, particularly in female patients. Conclusions The study highlights real-world challenges in the use of tolvaptan for ADPKD, particularly for side effects leading to high discontinuation rates and dosage adjustments. These findings underscore the need for standardized and improved management strategies to enhance tolerability and adherence, offering insights for future research and practice in the treatment of ADPKD with tolvaptan.

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common inherited kidney disorder and a leading cause of renal failure. While significant progress has been made in understanding ADPKD progression and treatment, gaps remain in early prognostic modeling, treatment implementation, and patient engagement. This dissertation addresses these challenges in three different studies. First, a longitudinal analysis of the Early PKD Observational Cohort (EPOC) demonstrates that kidney growth in pediatric and young adult ADPKD follows heterogenous nonlinear trajectories, with key risk factors in progression. This work highlights the need for age-specific risk stratification to predict long-term outcomes. Second, a real-world study of tolvaptan use in ADPKD patients across two U.S. medical centers provides insights into tolerability and adherence. Findings reveal a strong preference for lower-than-trial tolvaptan dosages in practice, underscoring the need for side-effect management and individualized dosing to optimize long-term use. Third, an evaluation of patient engagement in the PKD Research Resource Consortium (PKD RRC) explores how structured patient involvement can improve the development and accessibility of research resources. This study presents a novel conceptual framework for integrating patient perspectives into research design and infrastructure, positioning patient engagement as a critical research resource. Together, these studies aim to advance early ADPKD risk stratification, optimize treatment implementation, and integrate patient voices into research infrastructure. By bridging research and clinical care, this work aims to improve both scientific rigor and patient-centered outcomes in ADPKD management.