Effect of Perioperative Tranexamic Acid on Allogeneic Blood Transfusions for Total Knee Arthroplasty Patients at a Community Hospital.

Introduction Tranexamic acid (TXA) has been shown to be a cost-effective method for reducing blood loss and postoperative transfusions in patients undergoing total knee arthroplasty (TKA) at tertiary care centers. However, the efficacy of TXA has not been studied in community hospitals, and the potential cost savings may be especially beneficial for these institutions. The purpose of this study was to assess the effectiveness of TXA in reducing postoperative transfusions and blood loss following TKA at a community hospital. Methods Institutional approval was obtained for the retrospective review of a consecutive series of patients that underwent a total knee arthroplasty procedure between January 1, 2019, and December 31, 2019. Patients undergoing bilateral TKA were excluded from the analysis, yielding a total of 190 TKA procedures of which 131 patients received TXA. Fisher's exact test was conducted to compare rates of transfusion between the groups. A difference in difference analysis was conducted to assess TXA's effect on patient hemoglobin levels (Hgb) on postoperative Days 1 and 2. All analyses were conducted using R studio (Vienna, Austria). A p-value of 0.05 was set as the threshold for statistical significance. Results There was no difference in group characteristics in terms of age (70 years vs 68 years, p=0.17; no-TXA vs TXA, respectively). Fisher's exact test revealed no difference in the rates of allogeneic transfusion between TKA patients who did not receive a TXA and TKA patients who received a TXA (3.4% vs 0.8%; p=0.228). However, our difference in differences analysis revealed that TXA patients had a mean reduction in hemoglobin (Hgb)-related blood loss of 0.876 Hgb/dl (95% CI: 0.56 to 1.19; p<0.001) between the preoperative period and postoperative Day 1. Similarly, our difference in differences analysis revealed a mean reduction in Hgb-related blood loss of 0.972 Hgb/dl (95% CI: 0.593 to 1.349; p<0.001) between the preoperative period and postoperative Day 2. Conclusion The present study shows TXA to be effective for reducing blood loss and transfusions following TKAs performed at a small community hospital. Given the cost-savings previously reported with TXA use, as well as the medical benefits reported in this study, TXA may have a niche in small community hospitals where cost savings from reduced transfusions and shorter hospital stays are important. Further studies should assess the exact amount of financial savings from TXA utilization in small community hospitals.

Unbiased Phenotype-Based Screen Identifies Therapeutic Agents Selective for Metastatic Prostate Cancer.

In American men, prostate cancer is the second leading cause of cancer-related death. Dissemination of prostate cancer cells to distant organs significantly worsens patients' prognosis, and currently there are no effective treatment options that can cure advanced-stage prostate cancer. In an effort to identify compounds selective for metastatic prostate cancer cells over benign prostate cancer cells or normal prostate epithelial cells, we applied a phenotype-based in vitro drug screening method utilizing multiple prostate cancer cell lines to test 1,120 different compounds from a commercial drug library. Top drug candidates were then examined in multiple mouse xenograft models including subcutaneous tumor growth, experimental lung metastasis, and experimental bone metastasis assays. A subset of compounds including fenbendazole, fluspirilene, clofazimine, niclosamide, and suloctidil showed preferential cytotoxicity and apoptosis towards metastatic prostate cancer cells in vitro and in vivo. The bioavailability of the most discerning agents, especially fenbendazole and albendazole, was improved by formulating as micelles or nanoparticles. The enhanced forms of fenbendazole and albendazole significantly prolonged survival in mice bearing metastases, and albendazole-treated mice displayed significantly longer median survival times than paclitaxel-treated mice. Importantly, these drugs effectively targeted taxane-resistant tumors and bone metastases - two common clinical conditions in patients with aggressive prostate cancer. In summary, we find that metastatic prostate tumor cells differ from benign prostate tumor cells in their sensitivity to certain drug classes. Taken together, our results strongly suggest that albendazole, an anthelmintic medication, may represent a potential adjuvant or neoadjuvant to standard therapy in the treatment of disseminated prostate cancer.

Identification of genes regulating migration and invasion using a new model of metastatic prostate cancer.

BACKGROUND: Understanding the complex, multistep process of metastasis remains a major challenge in cancer research. Metastasis models can reveal insights in tumor development and progression and provide tools to test new intervention strategies. METHODS: To develop a new cancer metastasis model, we used DU145 human prostate cancer cells and performed repeated rounds of orthotopic prostate injection and selection of subsequent lymph node metastases. Tumor growth, metastasis, cell migration and invasion were analyzed. Microarray analysis was used to identify cell migration- and cancer-related genes correlating with metastasis. Selected genes were silenced using siRNA, and their roles in cell migration and invasion were determined in transwell migration and Matrigel invasion assays. RESULTS: Our in vivo cycling strategy created cell lines with dramatically increased tumorigenesis and increased ability to colonize lymph nodes (DU145LN1-LN4). Prostate tumor xenografts displayed increased vascularization, enlarged podoplanin-positive lymphatic vessels and invasive margins. Microarray analysis revealed gene expression profiles that correlated with metastatic potential. Using gene network analysis we selected 3 significantly upregulated cell movement and cancer related genes for further analysis: EPCAM (epithelial cell adhesion molecule), ITGB4 (integrin ß4) and PLAU (urokinase-type plasminogen activator (uPA)). These genes all showed increased protein expression in the more metastatic DU145-LN4 cells compared to the parental DU145. SiRNA knockdown of EpCAM, integrin-ß4 or uPA all significantly reduced cell migration in DU145-LN4 cells. In contrast, only uPA siRNA inhibited cell invasion into Matrigel. This role of uPA in cell invasion was confirmed using the uPA inhibitors, amiloride and UK122. CONCLUSIONS: Our approach has identified genes required for the migration and invasion of metastatic tumor cells, and we propose that our new in vivo model system will be a powerful tool to interrogate the metastatic cascade in prostate cancer.

Regulation of epithelial plasticity by miR-424 and miR-200 in a new prostate cancer metastasis model.

Using an in vivo cycling strategy, we selected metastatic cancer cells from the lymph nodes (LN) of mice bearing orthotopic DU145 human prostate tumors. Repeated rounds of metastatic selection (LN1-LN4) progressively increased the epithelial phenotype, resulting in a new model of tumor cell mesenchymal-epithelial transition (MET). DU145-LN4 showed increased cell-cell adhesions, higher expression of multiple epithelial markers, such as E-cadherin, EpCAM and cytokeratin 18, and reduced expression of mesenchymal markers such as vimentin. The MET in DU145-LN4 cells was accompanied by increased expression of the miR-200 family, and antimiRs to miR-200c and miR-141 induced an EMT. MET also correlated with the loss of miR-424. Ectopic transient and stable miR-424 expression induced EMT, with reduced epithelial marker expression and increased cell scattering. Our model provides evidence for spontaneous MET in vivo. We show that this cellular plasticity can be mediated through the combined action of miR-424 and the miR-200 family.

Multiple endocrine neoplasia type 1 deletion in pancreatic alpha-cells leads to development of insulinomas in mice.

The pancreatic alpha- and beta-cells are critical components in regulating blood glucose homeostasis via secretion of glucagon and insulin, respectively. Both cell types are typically localized in the islets of Langerhans. However, little is known about the roles of paracrine interactions that contribute to their physiological functions. The lack of suitable cell lines to study alpha- and beta-cells interactions have led us to develop an alpha-cell-specific Cre-expressing transgenic line utilizing a glucagon promoter sequence, the Glu-Cre transgenic mouse. Here, we demonstrate that the Glu-Cre could specifically and efficiently excise floxed target genes in adult islet alpha-cells. We further showed that deletion of the tumor suppressor gene, multiple endocrine neoplasia type 1 (Men1), in alpha-cells led to tumorigenesis. However, to our surprise, the lack of Men1 in alpha-cells did not result in glucagonomas but rather beta-cell insulinomas. Because deletion of the Men1 alleles was only present in alpha-cells, our data suggested that cross communication between alpha- and beta-cells contributes to tumorigenesis in the absence of Men1. Together, we believed that the new model systems described here will allow future studies to decipher cellular interactions between islet alpha- and beta-cells in a physiological context.

Stromal and epithelial networks: Temporal gene expression profiling during invasive neoplasia.

The interaction between tumor cells and the stromal microenvironment is a critical factor in cancer development and progression. A recent study from the Khavari group profiled the expression changes during progression to invasion in a Ras-inducible model of human epithelial neoplasia and used network modeling to analyze the molecular interactions. Human dermis was seeded with H-Ras- and IkappaBalpha-expressing keratinocytes then grafted on to immune-deficient mice. The epithelial and stromal gene expression profiles were captured during progression from quiescent epithelial tissue to in situ neoplasia to invasive neoplasia. A subset of these altered genes was compiled into a "core tumor progression signature" (CTPS), which was shown to have clinical relevance in several cancer types. Network modeling of the CTPS revealed highly interconnected "hubs", which was dominated by extracellular matrix-related genes, including beta(1) integrin. Targeting integrin beta(1) functionality reduced Ras-driven tumorigenesis in vivo and validated the network modeling strategy for predicting genes essential to neoplasia. By integrating temporal analysis of both the epithelial and stromal compartments with network modeling of molecular interactions, this work has described an effective strategy for identifying highly interconnected targets essential to tumor development.

Current molecular diagnostics of breast cancer and the potential incorporation of microRNA.

Although comprehensive molecular diagnostics and personalized medicine have sparked excitement among researchers and clinicians, they have yet to be fully incorporated into today's standard of care. This is despite the discovery of disease-related oncogenes, tumor-suppressor genes and protein biomarkers, as well as other biological anomalies related to cancer. Each year, new tests are released that could potentially supplement or surpass standard methods of diagnosis, including serum, protein and gene expression analyses. All of these novel approaches have shown great promise, but initial enthusiasm has diminished as difficulties in reproducibility, expense, standardization and proof of significance beyond current protocols have emerged. This review will focus on current and novel molecular diagnostic tools applied to breast cancer with special attention to the exciting new field of microRNA analysis.

Deciphering von Hippel-Lindau (VHL/Vhl)-associated pancreatic manifestations by inactivating Vhl in specific pancreatic cell populations.

The von Hippel-Lindau (VHL) syndrome is a pleomorphic familial disease characterized by the development of highly vascularized tumors, such as hemangioblastomas of the central nervous system, pheochromocytomas, renal cell carcinomas, cysts and neuroendocrine tumors of the pancreas. Up to 75% of VHL patients are affected by VHL-associated pancreatic lesions; however, very few reports in the published literature have described the cellular origins and biological roles of VHL in the pancreas. Since homozygous loss of Vhl in mice resulted in embryonic lethality, this study aimed to characterize the functional significance of VHL in the pancreas by conditionally inactivating Vhl utilizing the Cre/LoxP system. Specifically, Vhl was inactivated in different pancreatic cell populations distinguished by their roles during embryonic organ development and their endocrine lineage commitment. With Cre recombinase expression directed by a glucagon promoter in alpha-cells or an insulin promoter in beta-cells, we showed that deletion of Vhl is dispensable for normal functions of the endocrine pancreas. In addition, deficiency of VHL protein (pVHL) in terminally differentiated alpha-cells or beta-cells is insufficient to induce pancreatic neuroendocrine tumorigenesis. Most significantly, we presented the first mouse model of VHL-associated pancreatic disease in mice lacking pVHL utilizing Pdx1-Cre transgenic mice to inactivate Vhl in pancreatic progenitor cells. The highly vascularized microcystic adenomas and hyperplastic islets that developed in Pdx1-Cre;Vhl f/f homozygous mice exhibited clinical features similar to VHL patients. Establishment of three different, cell-specific Vhl knockouts in the pancreas have allowed us to provide evidence suggesting that VHL is functionally important for postnatal ductal and exocrine pancreas, and that VHL-associated pancreatic lesions are likely to originate from progenitor cells, not mature endocrine cells. The novel model systems reported here will provide the basis for further functional and genetic studies to define molecular mechanisms involved in VHL-associated pancreatic diseases.