Vascular endothelial cells maintain the interface between the systemic circulation and soft tissues and mediate critical processes such as inflammation in a vascular bed-selective fashion. To expand our understanding of the genetic pathways that underlie these specific functions, we have focused on the identification of novel genes that are differentially expressed in all endothelial cells, as well as restricted groups of this cell type. Virtual subtraction was conducted employing gene expression data deposited in public databases and 384 genes identified. These genes were spotted on custom microarrays, along with 288 genes identified through subtraction cloning from TGF-beta-stimulated endothelial cells. Arrays were evaluated with RNA samples representing endothelial cells cultured from four vascular sources and five non-endothelial cell types. These studies identified 64 pan-endothelial markers that were differentially expressed with at least a threefold difference (range 3- to 55-fold). In addition, differences in gene expression profiles among endothelial cells from different vascular beds were identified. Validation of these findings was performed by RNA blot expression studies, and a number of the novel genes were shown to be expressed under angiogenic conditions in the developing mouse embryo. The combined tools of database mining and transcriptional profiling thus provide expanded knowledge of endothelial cell gene expression and endothelial cell biology.

mal and epidermal precursor cells undergo phenotypic changes during differentiation to the smooth muscle cell (SMC) lineage that are relevant to pathophysiological processes in the adult. Molecular mechanisms that underlie lineage determination and terminal differentiation of this cell type have received much attention, but the genetic program that regulates these processes has not been fully defined. Study of SMC differentiation has been facilitated by development of the P19-derived A404 embryonal cell line, which differentiates toward this lineage in the presence of retinoic acid and allows selection for cells adopting a SMC fate through a differentiation-specific drug marker. We sought to define global alterations in gene expression by studying A404 cells during SMC differentiation with oligonucleotide microarray transcriptional profiling. Using an in situ 60-mer array platform with more than 20,000 mouse genes derived from the National Institute on Aging clone set, we identified 2,739 genes that were significantly upregulated after differentiation was completed (false-detection ratio Ͻ1). These genes encode numerous markers known to characterize differentiated SMC, as well as many unknown factors. We further characterized the sequential patterns of gene expression during the differentiation time course, particularly for known transcription factor families, providing new insights into the regulation of the differentiation process. Changes in genes associated with specific biological ontologybased pathways were evaluated, and temporal trends were identified for functional pathways. In addition to confirming the utility of the A404 model, our data provide a large-scale perspective of gene regulation during SMC differentiation.

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Background: The use of HER2 targeting therapy has revolutionized the treatment of HER2 positive breast cancers. Here, we investigate whether a sequential approach to dual HER2 blockade of lapatinib followed by trastuzumab will result in improved clinical outcomes. Methods: This was a single institution, open label, single arm, phase II trial in women with HER2 positive breast cancer. Volunteers were treated with sequential neoadjuvant doxorubicin (60 mg/m 2 ) and cyclophosphamide (600 mg/m 2 ) (AC) for 4 cycles followed by docetaxel (100 mg/m 2 ) concurrent with lapatinib (1,250 mg) (TL) daily for 21 days for four cycles before definitive surgery. The primary end point was pathologic complete response (pCR).Results: The study accrued only 21 of the 71 planned patients from 2/28/2007 to 5/25/2010. All patients (100%) experienced down staging. The pCR rate was 41% (7/18). 11 patients had tumor size of T3 or greater, 3 of which experienced pCR and only 1 underwent breast conservation (lumpectomy). The most common hematologic AE (all grades) was anemia 17/21 (81%). There were no incidences of grade 3 or 4 anemia. 10 of 21 (48%) patients experience a non-hematologic grade 3 AE. The most common non-hematologic AEs (all grades) were irregular menses 20/21 (95%) and hand-foot-skin reactions 20/21 (95%). No increase cardiac abnormalities were noted. The DFS at data cut off was 87.5%. Conclusion:The provocative pCR and DFS results in this high risk locally advanced patient population should be viewed with caution given results of the Adjuvant Lapatinib And/Or Trastuzumab Treatment Optimisation study (ALTTO) clinical trial.

e19030 Background: Lintuzumab-Ac225 is a humanized CD33 antibody conjugated to an alpha emitting isotope, Ac225, delivering high energy radiation to CD33 expressing AML blasts. Preclinical studies indicate Lintuzumab-Ac225 also depletes the anti-apoptotic protein MCL-1, which is a known resistance factor in BCL2-inhibitor (venetoclax (Ven)) exposed patients (pts). We performed a Phase I study where Lintuzumab-Ac225 was administered after salvage chemotherapy, and this study demonstrated safety and encouraging response rates in R/R AML. Herein, we report results of high-risk patients who enrolled to this study. Methods: R/R AML pts deemed fit, and with CD33 expression on >25% of blasts were enrolled onto a Phase I study, Lintuzumab-Ac225 in Combination with Cladribine + Cytarabine + Filgrastim + Mitoxantrone (CLAG-M). Induction consisted of G-CSF, 300mcg/d on D1-6, cladribine 5mg/m2 on D2-6, cytarabine 2g/m2 on D2-6, and mitoxantrone 10mg/m2 on D2-4. Lintuzumab-Ac225 was administered once on D8 ±1 day. The trial enrolled to 4 cohorts, with Lintuzumab-Ac225 at doses ranging from 0.25 uCi/kg to 1.0 uCi/kg. We defined high-risk pts as those who met ELN 2019 criteria for adverse risk disease, or pts who received a Ven combination prior to trial enrollment. Response is descriptively reported, and KM estimator was used to report overall survival (OS). Results: 19 pts on trial met high-risk criteria. Of these, 16 pts had ELN adverse risk disease, a TP53 mutation was detected in 75% (n=12) of pts. Median age was 65 yrs, pts received a median 2 lines of prior therapy, including prior allo-HCT in 58% (n=11), and prior Ven combination in 68% (n=13) of pts. In high-risk pts, 42% (n=8) of pts achieved CRc (CR+CRi), 16% (n=3) achieved MLFS, for an overall response rate (ORR) of 58%. Among evaluable pts achieving CRc, 71% achieved flow MRD negativity. Median OS was 7.4 months. Table reports results in select subgroups. Prior to treatment initiation, 7 pts were deemed eligible for first HCT. 4 (57%) were successfully able to bridge to HCT. Median survival among transplanted pts was 28 months. Post-HCT, one pt died due to GVHD, one due to relapse. Conclusions: CLAG-M in combination with Lintuzumab-Ac225 yielded significantly better clinical outcomes in high-risk populations, particularly in pts previously treated with Ven combinations (median OS 13.8 mo.) and in pts with TP53 mutations (median OS 7.3 mo.), for which recent studies have reported a survival of 4 months or less. The results support further advance in late-stage clinical development of Lintuzumab-Ac225 in combination with CLAG-M in R/R AML, especially in high-risk pts. Clinical trial information: NCT03441048 . [Table: see text]