Syndecan-1 facilitates breast cancer metastasis to the brain.

PURPOSE: Although survival rates for patients with localized breast cancer have increased, patients with metastatic breast cancer still have poor prognosis. Understanding key factors involved in promoting breast cancer metastasis is imperative for better treatments. In this study, we investigated the role of syndecan-1 (Sdc1) in breast cancer metastasis. METHODS: To assess the role of Sdc1 in breast cancer metastasis, we silenced Sdc1 expression in the triple-negative breast cancer human MDA-MB-231 cell line and overexpressed it in the mouse mammary carcinoma 4T1 cell line. Intracardiac injections were performed in an experimental mouse metastasis model using both cell lines. In vitro transwell blood-brain barrier (BBB) and brain section adhesion assays were utilized to specifically investigate how Sdc1 facilitates brain metastasis. A cytokine array was performed to evaluate differences in the breast cancer cell secretome when Sdc1 is silenced. RESULTS: Silencing expression of Sdc1 in breast cancer cells significantly reduced metastasis to the brain. Conversely, overexpression of Sdc1 increased metastasis to the brain. We found that silencing of Sdc1 expression had no effect on attachment of breast cancer cells to brain endothelial cells or astrocytes, but migration across the BBB was reduced as well as adhesion to the perivascular regions of the brain. Loss of Sdc1 also led to changes in breast cancer cell-secreted cytokines/chemokines, which may influence the BBB. CONCLUSIONS: Taken together, our study demonstrates a role for Sdc1 in promoting breast cancer metastasis to the brain. These findings suggest that Sdc1 supports breast cancer cell migration across the BBB through regulation of cytokines, which may modulate the BBB. Further elucidating this mechanism will allow for the development of therapeutic strategies to combat brain metastasis.

Persistent organic pollutants (POPs) increase rage signaling to promote downstream cardiovascular remodeling.

Exposure to environmental contaminants and consumption of a high, saturated fatty diet has been demonstrated to promote precursors for metabolic syndrome (hyperglycemia, hyperinsulinemia, and hypertriglyceridemia). The purpose of this study was to determine if exposure to the most prevalent environmental persistent organic pollutants (POPs) would act as causative agents to promote metabolic syndrome independent of dietary intake. We hypothesized that POPs will activate the advanced glycated end-product (AGE)-and receptor for AGE (RAGE) signaling cascade to promote downstream signaling modulators of cardiovascular remodeling and oxidative stress in the heart. At 5-weeks of age nondiabetic (WT) and diabetic (ob/ob) mice were exposed POPs mixtures by oral gavage twice a week for 6-weeks. At the end of 6-weeks, animals were sacrificed and the hearts were taken for biochemical analysis. Increased activation of the AGE-RAGE signaling cascade via POPs exposure resulted in elevated levels of fibroblast differentiation (α-smooth muscle actin) and RAGE expression indicated maladaptive cardiac remodeling. Conversely, the observed decreased superoxide dismutase-1 and -2 (SOD-1 and SOD-2) expression may exacerbate the adverse changes occurring as a result of POPs treatment to reduce innate cardioprotective mechanisms. In comparison, ventricular collagen levels were decreased in mice exposed to POPs. In conclusion, exposure to organic environmental pollutants may intensify oxidative and inflammatory stressors to overwhelm protective mechanisms allowing for adverse cardiac remodeling.

High grade infiltrative adenocarcinomas of renal cell origin: New insights into classification, morphology, and molecular pathogenesis.

Collecting duct carcinoma was described over 30 years ago as a renal tumor, based in the medullary collecting system, with tubulopapillary morphology, prominent infiltrative growth, and stromal desmoplasia. While diagnostic workup has always emphasized exclusion of upper tract urothelial carcinoma and metastatic adenocarcinoma to the kidney, the molecular era of renal cell carcinoma classification has enabled recognition of and provided tools for diagnosis of new entities in this morphologic differential. In this review, we consider these developments, with emphasis on renal medullary carcinoma, closely related renal cell carcinoma, unclassified with medullary phenotype, and fumarate hydratase-deficient renal cell carcinoma. Integration of ancillary studies with suggestive patterns of morphology is emphasized for practical implementation in contemporary diagnosis, and several emerging tumor types in the morphologic differential are presented.

Complete Pathologic Response to Gemcitabine and Oxaliplatin Chemotherapy After Prior Therapies in a Patient With Hepatocellular Carcinoma and Peritoneal Metastases Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

Hepatocellular carcinoma (HCC) is often diagnosed at a late stage and frequently recurs despite curative intervention, leading to poor survival outcomes. Frontline systemic therapies include combination immunotherapy regimens and tyrosine kinase inhibitors. We report a case of a 38-year-old woman with chronic hepatitis B and C coinfection-associated non-cirrhotic HCC, which recurred in the peritoneum after initial resection of her primary tumor. Disease progression occurred on both atezolizumab/bevacizumab and lenvatinib, and she was subsequently treated with gemcitabine and oxaliplatin (GEMOX) chemotherapy and exhibited a profound clinical response on imaging with normalization of alpha fetoprotein (AFP) after several months. Following extensive multidisciplinary discussion, she underwent cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) that removed all visible macroscopic tumor. Her pathology demonstrated a complete pathologic response. She received two additional months of postoperative chemotherapy, and then proceeded with close monitoring off therapy. To our knowledge, this is the first reported case of a complete pathologic response to GEMOX chemotherapy in the context of CRS/HIPEC for peritoneal metastases in HCC, after progression on standard immunotherapy and tyrosine kinase inhibitor treatments. In this report, we review the current systemic treatment landscape in HCC. We highlight potential consideration of cytotoxic chemotherapy, which is less frequently utilized in current practice, in selected patients with HCC, and discuss the role of CRS/HIPEC in the management of peritoneal metastases. Further investigation regarding predictors of response to systemic treatments is strongly needed. Multidisciplinary management may ultimately prolong survival in patients with advanced HCC.

Effective Delivery of a Microtubule Polymerization Inhibitor Synergizes with Standard Regimens in Models of Pancreatic Ductal Adenocarcinoma.

PURPOSE: Pancreatic ductal adenocarcinoma (PDA) is a deadly cancer that is broadly chemoresistant, due in part to biophysical properties of tumor stroma, which serves as a barrier to drug delivery for most classical chemotherapeutic drugs. The goal of this work is to evaluate the preclinical efficacy and mechanisms of PTC596, a novel agent with potent anticancer properties in vitro and desirable pharmacologic properties in vivo.Experimental Design: We assessed the pharmacology, mechanism, and preclinical efficacy of PTC596 in combination with standards of care, using multiple preclinical models of PDA. RESULTS: We found that PTC596 has pharmacologic properties that overcome the barrier to drug delivery in PDA, including a long circulating half-life, lack of P-glycoprotein substrate activity, and high systemic tolerability. We also found that PTC596 combined synergistically with standard clinical regimens to improve efficacy in multiple model systems, including the chemoresistant genetically engineered "KPC" model of PDA. Through mechanistic studies, we learned that PTC596 functions as a direct microtubule polymerization inhibitor, yet a prior clinical trial found that it lacks peripheral neurotoxicity, in contrast to other such agents. Strikingly, we found that PTC596 synergized with the standard clinical backbone regimen gemcitabine/nab-paclitaxel, yielding potent, durable regressions in a PDX model. Moreover, similar efficacy was achieved in combination with nab-paclitaxel alone, highlighting a specific synergistic interaction between two different microtubule-targeted agents in the setting of pancreatic ductal adenocarcinoma. CONCLUSIONS: These data demonstrate clear rationale for the development of PTC596 in combination with standard-of-care chemotherapy for PDA.