[NEOADJUVANT TREATMENT OF LOCALLY ADVANCED ESTROGEN/PROGESTERONE POSITIVE, HER2NEU NEGATIVE BREAST CANCER].

INTRODUCTION: Women who present with locally advanced breast cancer that would require a mastectomy are often recommended to undergo chemotherapy prior to surgery in hopes of down-staging the tumor and allowing for breast-conserving surgery. This approach is very effective in women with triple negative and Her2neu positive locally advanced breast cancer, yet the results in ER/PR positive (luminal) breast cancers have been less effective. In post-menopausal women, neoadjuvant hormonal treatment in such cases can cause tumor regression and allow for breast-conserving therapy, in some patients. In premenopausal women with locally advanced luminal type breast cancer, neoadjuvant hormonal therapy can also be effective and is a valid option according to the NCCN guidelines. Yet, there remains a sense that perhaps treatment of this group of patients with chemotherapy results in better outcomes. For the past fifteen years various molecular profiles of luminal breast cancers have been studied and have been used to help guide decisions as to the benefit of adjuvant treatment - whether chemotherapy is necessary or hormonal therapy alone would be adequate. In the neo-adjuvant setting, these profiles can also help predict which tumors are likely to respond to chemotherapy and which are less likely to respond. The only hormonal drugs available until very recently for use in the neoadjuvant setting were either Tamoxifen or an aromatase inhibitor. In the past few years a new class of drugs, CDK4/6 inhibitors have been developed and approved and have significantly improved response rates and time to progression in patients with metastatic hormone responsive breast cancer, and they have also been studied in small trials in the neoadjuvant setting. In this article we will review the data that is available to help guide the optimal choice of treatment in women who present with locally advanced luminal breast cancers including the use of molecular profiles and the potential role of anti-CDK 4/6 drugs.

An optimized protocol for generating labeled and transplantable photoreceptor precursors from human embryonic stem cells.

Cell replacement therapy is a promising approach for treatment of retinal degenerative diseases. Several protocols for the generation of photoreceptor precursors (PRP) from human embryonic stem cells (hESC) have been reported with variable efficiency. Herein, we show the advantages of use of size-controlled embryoid bodies in the ESC differentiation process using two differentiation protocols. We further explored cell-labeling methods for following the survival of PRP transplanted subretinally in rat eyes. Size-controlled embryoid bodies (EBs) generated using microwell dishes and non-size-controlled EBs generated using V-shaped 96-well plates were differentiated into PRP using two differentiation protocols. The differentiation protocols utilized two different combinations of growth factors. The first, Dkk1, Noggin, and IGF1, and the second protocol used IWR1e, SAG, and CHIR99021. Differentiation efficiency to PRP was analyzed by qPCR, immunocytochemistry, and fluorescence-assisted cell sorting (FACS). Size-controlled IWR1e yielded a significantly higher percent (86.4%) of PRP cells expressing CRX, compared with non-size-controlled IWR1e (51.4%, P = 0.026) or the size-controlled DKK1 protocol (70.5%, p = 0.007). In addition, the IWR1e differentiated cells exhibited a significantly higher fluorescence intensity of CRX immunostaining, compared with the DKK1 protocol, consistent with higher protein expression levels. The IWR1e cells exhibited higher maturation levels, as manifested by lower early neuronal marker PAX6 and pluripotency marker OCT4 levels compared with the DKK1 protocol. The expression of other late photoreceptor markers (NRL, recoverin) were similar among the differentiation groups. PRP cells were labeled by using hESC constitutively expressing EGFP or by AAV-GFP transduction. Finally, we transplanted the cells in the subretinal space of wild-type rats and monitored their survival over several weeks. The AAV2 serotype efficiently transduced the PRP cells, whereas other serotypes yielded low or no transduction. Following subretinal transplantation of GFP-labeled PRP, 63% of the cells were detected at 4 weeks post-transplantation. In conclusion, we show here that the IWR1e protocol using size-controlled EBs efficiently generated of PRP that could be labeled and followed in-vivo for weeks. The data from this study is an advance toward the goal of PRP transplantation therapy for retinal degenerative diseases.

MicroRNA-486-5p is an erythroid oncomiR of the myeloid leukemias of Down syndrome.

Children with Down syndrome (DS) are at increased risk for acute myeloid leukemias (ML-DS) characterized by mixed megakaryocytic and erythroid phenotype and by acquired mutations in the GATA1 gene resulting in a short GATA1s isoform. The chromosome 21 microRNA (miR)-125b cluster has been previously shown to cooperate with GATA1s in transformation of fetal hematopoietic progenitors. In this study, we report that the expression of miR-486-5p is increased in ML-DS compared with non-DS acute megakaryocytic leukemias (AMKLs). miR-486-5p is regulated by GATA1 and GATA1s that bind to the promoter of its host gene ANK1. miR-486-5p is highly expressed in mouse erythroid precursors and knockdown (KD) in ML-DS cells reduced their erythroid phenotype. Ectopic expression and KD of miR-486-5p in primary fetal liver hematopoietic progenitors demonstrated that miR-486-5p cooperates with Gata1s to enhance their self renewal. Consistent with its activation of AKT, overexpression and KD experiments showed its importance for growth and survival of human leukemic cells. Thus, miR-486-5p cooperates with GATA1s in supporting the growth and survival, and the aberrant erythroid phenotype of the megakaryocytic leukemias of DS.

Echocardiography vs hemodynamic assessment of diastolic dysfunction.

OBJECTIVES: Ostial CTOs can be challenging to revascularize. We aim to describe the outcomes of ostial chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We examined the clinical and angiographic characteristics and procedural outcomes of 8788 CTO PCIs performed at 35 US and non-US centers between 2012 and 2022. In-hospital major adverse cardiac events (MACE) included death, myocardial infarction, urgent repeat target-vessel revascularization, tamponade requiring pericardiocentesis or surgery, and stroke. RESULTS: Ostial CTOs constituted 12% of all CTOs. Patients with ostial CTOs had higher J-CTO score (2.9 ± 1.2 vs 2.3 ± 1.3; P less than .01). Ostial CTO PCI had lower technical (82% vs. 86%; P less than .01) and procedural (81% vs. 85%; P less than .01) success rates compared with non-ostial CTO PCI. Ostial location was not independently associated with technical success (OR 1.03, CI 95% 0.83-1.29 P =.73). Ostial CTO PCI had a trend towards higher incidence of MACE (2.6% vs. 1.8%; P =.06), driven by higher incidence of in-hospital death (0.9% vs 0.3% P less than.01) and stroke (0.5% vs 0.1% P less than .01). Ostial lesions required more often use of the retrograde approach (30% vs 9%; P less than .01). Ostial CTO PCI required longer procedure time (149 [103,204] vs 110 [72,160] min; P less than .01) and higher air kerma radiation dose (2.3 [1.3, 3.6] vs 2.0 [1.1, 3.5] Gray; P less than .01). CONCLUSIONS: Ostial CTOs are associated with higher lesion complexity and lower technical and procedural success rates. CTO PCI of ostial lesions is associated with frequent need for retrograde crossing, higher incidence of death and stroke, longer procedure time and higher radiation dose.

Slow Transcription of the 99a/let-7c/125b-2 Cluster Results in Differential MiRNA Expression and Promotes Melanoma Phenotypic Plasticity.

Almost half of the human microRNAs (miRNAs) are encoded in clusters. Although transcribed as a single unit, the levels of individual mature miRNAs often differ. The mechanisms underlying differential biogenesis of clustered miRNAs and the resulting physiological implications are mostly unknown. In this study, we report that the melanoma master transcription regulator MITF regulates the differential expression of the 99a/let-7c/125b-2 cluster by altering the distribution of RNA polymerase II along the cluster. We discovered that MITF interacts with TRIM28, a known inhibitor of RNA polymerase II transcription elongation, at the mIR-let-7c region, resulting in the pausing of RNA polymerase II activity and causing an elevation in mIR-let-7c expression; low levels of RNA polymerase II occupation over miR-99a and miR-125b-2 regions decreases their biogenesis. Furthermore, we showed that this differential expression affects the phenotypic state of melanoma cells. RNA-sequencing analysis of proliferative melanoma cells that express miR-99a and miR-125b mimics revealed a transcriptomic shift toward an invasive phenotype. Conversely, expression of a mIR-let-7c mimic in invasive melanoma cells induced a shift to a more proliferative state. We confirmed direct target genes of these miRNAs, including FGFR3, BAP1, Bcl2, TGFBR1, and CDKN1A. Our study demonstrates an MITF-governed biogenesis mechanism that results in differential expression of clustered 99a/let-7c/125b-2 miRNAs that control melanoma progression.