Sample, Jack W

(1) Background: Mammographic breast density (MBD) is a well-established predictor of breast cancer risk, yet the biological mechanisms underlying this association remain incompletely understood. MBD is characterized by alterations in breast stromal architecture, including increased collagen deposition and changes in immune cell composition. Given emerging evidence that the breast harbors a resident microbiome, we investigated whether the breast tissue microbiome correlates with MBD. (2) Methods: Adjacent normal breast tissue was collected under sterile conditions from 33 women undergoing surgery for benign or malignant breast disease. DNA was extracted and subjected to 16S rRNA gene sequencing (Illumina MiSeq). (3) Results: We observed a non-significant trend toward lower α-diversity in high-MBD samples compared to low-MBD samples, p = 0.13. β-Diversity analyses identified a modest association between MBD and microbial community composition (MiRKAT p = 0.049). A random forest-based model incorporating genus-level relative abundances improved prediction of MBD over clinical characteristics alone, identifying Corynebacterium (Actinobacteria) and other genera as key predictors. (4) Conclusions: Breast tissue microbial features vary with mammographic breast density, suggesting a potential association with density-associated breast cancer risk. These exploratory findings warrant validation in larger cohorts to better elucidate biological mechanisms and clinical relevance.

ABSTRACT EPHA2 is a receptor tyrosine kinase highly expressed in many cancers. By analyzing cancer patient databases for mutations in the EPHA2 coding sequence, we found that cholangiocarcinoma (a hepatobiliary cancer with dismal prognosis) exhibits a uniquely high incidence of EPHA2 mutations. To deUine the functional signiUicance of these mutations, we generated representative EPHA2 mutants and monitored major receptor autophosphorylation sites as indicative of kinase activity-dependent signal transduction (known as forward signaling). We found that missense mutations in the ligand-binding domain abrogate ligand binding and ligand-induced EPHA2 tyrosine phosphorylation, while most missense mutations in the kinase domain abrogate kinase activity. We detected less pronounced effects of missense mutations in other domains, which vary depending on the phosphosite, suggesting that these EPHA2 mutations might differentially affect (or bias) different downstream signaling pathways. Other EPHA2 mutations introduce early stop codons and encode receptor truncated forms lacking all or part of the kinase domain. We also found that an EPHA2 secreted truncated form, a transmembrane truncated form, and a full-length kinase inactive mutant can inhibit tyrosine phosphorylation of co-expressed EPHA2 wild-type. Taken together, these data suggest that mutations interfering with EPHA2 forward signaling facilitate cholangiocarcinoma development. We indeed obtained evidence that an EPHA2 kinase inactive mutant, but not EPHA2 wild-type, can induce proliferative masses consistent with well differentiated cholangiocarcinoma in a validated mouse model of cholangiocarcinogenesis. Taken together, our Uindings suggest that EPHA2 is a driver gene in cholangiocarcinoma and that its forward signaling has tumor suppressor activity.

Background and Aims: Cholangiocarcinoma (CCA) is an aggressive malignancy arising from the biliary epithelium with limited therapeutic options and poor long-term survival rates. To address the limitations of CCA treatment, we investigated cell-targeted nanovesicles as a delivery platform for transcriptome-targeting therapeutics. Approach and Results: Milk-derived nanovesicles were loaded with short interfering RNAs targeting Yes-associated protein (YAP), the downstream effector of the Hippo pathway; LCK, an upstream regulator of YAP; and tafazzin, a protein critical for the integrity of the inner mitochondrial membrane. These transcriptome-targeting nanovesicles were decorated with a lipid-coupled RNA aptamer to epithelial cell adhesion molecule, including a tracking fluorophore. In vitro studies were conducted using multiple CCA cell lines. In vivo studies were performed using C57BL/6 and non-obese diabetic/severe combined immunodeficient mice to evaluate delivery and efficacy in both an immunocompetent syngeneic murine and a patient-derived xenograft model. We demonstrated that transcriptome-targeting nanovesicles were selectively taken up by liver tumor cells, which was augmented by the incorporation of a targeting aptamer, and that milk-derived nanovesicles loaded with short interfering RNA effectively downregulated target gene expression, both in vitro and in vivo. Downstream effects of target gene inhibition were observed, including downregulation of YAP-TEAD target genes and an increase in reactive oxygen species production at the mitochondrial level. Administration of transcriptome-targeting nanovesicles targeting YAP, LCK, and tafazzin inhibited CCA growth and further synergized with chemotherapy in 2 preclinical CCA models. Conclusions: Herein, we show that aptamer-directed, nanovesicle-mediated targeting of YAP, LCK, and tafazzin potentiates chemosensitivity in 2 CCA models when delivered using aptamer-guided milk-derived nanovesicles.

Cholangiocarcinoma (CCA) is a highly aggressive form of liver cancer and is an increasing cause of cancer‐related death worldwide. Despite its increasing incidence globally and alarming mortality, treatment options for CCA have largely remained unchanged, stressing the importance of developing new effective therapies. YAP activation is common in CCA, and its major transcriptional signaling partners are the TEAD proteins. CA3 is a small‐molecule YAP‐TEAD disrupter discovered utilizing a TEAD reporter assay. Utilizing CCA, gastric cancer cell lines, and patient‐derived xenograft models (PDX), we demonstrate that CA3 is effective in inducing cell death and delaying tumor growth in both FGFR2 fusion and wild‐type models. CA3 was associated with on‐target decreases in YAP‐TEAD target gene expression, TEAD reporter activity, and overall TEAD levels. Hippo pathway signaling was not altered as there was no change in YAP phosphorylation status in the cells exposed to CA3. RNA sequencing of gastric cancer and CCA models demonstrated upregulation of an androgen receptor–mediated transcriptional program following exposure to CA3 in five unique models tested. Consistent with this upstream regulator analysis, CA3 exposure in CCA cells was associated with increased AR protein levels, and combinatorial therapy with CA3 and androgen receptor blockade was associated with increased cancer cell death. CA3 behaves functionally as a YAP‐TEAD disrupter in the models tested and demonstrated therapeutic efficacy. Exposure to CA3 was associated with compensatory androgen receptor signaling and dual inhibition improved the therapeutic effect.

Metabolic and bariatric surgery (MBS) is the most effective and durable therapeutic intervention for patients with obesity. In recent years, laparoscopic sleeve gastrectomy (SG) has become the most commonly performed primary MBS procedure owing to its technical feasibility and excellent short-term outcomes. Despite these favorable results and perceived advantages, SG is associated with several unique complications. Complications such as a postoperative leak or bleeding have been more commonly observed and reported than others, and their management approaches are well described. However, other complications following SG are far less familiar to surgeons, which may delay recognition and result in poor patient outcomes. Of these complications, we describe splenic injuries; esophageal perforation; staple line malformations; stapling of intraluminal devices; phytobezoar formation; gastro-colic, gastro-pleural and gastro-bronchial fistula; pancreatic leak; and portomesenteric venous thrombosis. It is paramount for surgeons to be aware of these underreported issues and have the resources to learn how to recognize and manage them when they arise. This review aims to describe rare (i.e., reported incidence <1%) and underdescribed complications after SG, focusing on causes, clinical presentation, prevention strategies, and management.

Metabolic and bariatric surgery (MBS) is the most effective therapeutic intervention for patients with obesity, with sleeve gastrectomy (SG) being the most commonly performed primary MBS procedure. Long-term studies have demonstrated that 15–20% of patients require revisional bariatric surgery (RBS) due to weight-related issues or surgical complications. Despite the gold standard being laparoscopic revision, there are other available approaches such as open or robotic-assisted. An extensive literature review was performed for articles from their inception to February 2024. A descriptive review of MBS procedures (SG, Roux-en-Y gastric bypass (RYGB), single anastomosis duodeno-ileostomy (SADI) and biliopancreatic diversion-duodenal switch (BPD-DS)) was carried out to report and compare outcomes between primary and revisional bariatric surgery. A similar review was conducted to compare outcomes of revisional approaches (open, laparoscopic, robotic). RYGB remains the dominant RBS with a similar safety profile compared to revisional SADI and BPD-DS. In terms of the RBS surgical approach, all three options showed comparable short and long-term outcomes, with robotic RBS being associated with longer operative time and variable length of stay. Additional long-term studies are required to further validate our conclusions.