Clathrin-dependent endocytosis of membrane-bound RANKL in differentiated osteoclasts

Bone is continuously repaired and remodelled through well-coordinated activity of osteoblasts that form new bone and osteoclasts, which resorb it. Osteoblasts synthesize and secrete two key molecules that are important for osteoclast differentiation, namely the ligand for the receptor of activator of nuclear factor κB (RANKL) and its decoy receptor osteoprotegerin (OPG). Active membrane transport is a typical feature of the resorbing osteoclast during bone resorption. Normally, one resorption cycle takes several hours as observed by monitoring actin ring formation and consequent disappearance in vitro. During these cyclic changes, the cytoskeleton undergoes remarkable dynamic rearrangement. Active cells show a continuous process of exocytosis that plays an essential role in transport of membrane components, soluble molecules and receptor-mediated ligands thus allowing them to communicate with the environment. The processes that govern intracellular transport and trafficking in mature osteoclasts are poorly known. The principal methodological problem that have made these studies difficult is a physiological culture of osteoclasts that permit observing the vesicle apparatus in conditions similar to the in vivo conditions. In the present study we have used a number of morphological approaches to characterize the composition, formation and the endocytic and biosynthetic pathways that play roles in dynamics of differentiation of mature bone resorbing cells using a tri-dimensional system of physiologic coculture

AMP-dependent kinase/mammalian target of rapamycin complex 1 signaling in T-cell acute lymphoblastic leukemia: therapeutic implications.

The mammalian target of rapamycin (mTOR) serine/threonine kinase is the catalytic subunit of two multi-protein complexes, referred to as mTORC1 and mTORC2. Signaling downstream of mTORC1 has a critical role in leukemic cell biology by controlling mRNA translation of genes involved in both cell survival and proliferation. mTORC1 activity can be downmodulated by upregulating the liver kinase B1/AMP-activated protein kinase (LKB1/AMPK) pathway. Here, we have explored the therapeutic potential of the anti-diabetic drug, metformin (an LKB1/AMPK activator), against both T-cell acute lymphoblastic leukemia (T-ALL) cell lines and primary samples from T-ALL patients displaying mTORC1 activation. Metformin affected T-ALL cell viability by inducing autophagy and apoptosis. However, it was much less toxic against proliferating CD4þ T-lymphocytes from healthy donors. Western blot analysis demonstrated dephosphorylation of mTORC1 downstream targets. Unlike rapamycin, we found a marked inhibition of mRNA translation in T-ALL cells treated with metformin. Remarkably, metformin targeted the side population of T-ALL cell lines as well as a putative leukemia-initiating cell subpopulation (CD34þ/CD7/CD4) in patient samples. In conclusion, metformin displayed a remarkable anti-leukemic activity, which emphasizes future development of LKB1/AMPK activators as clinical candidates for therapy in T-ALL. Leukemia (2012) 26, 91–100; doi:10.1038/leu.2011.269; published online 4 October 201

Is routine axillary lymph node dissection needed to tailor systemic treatments for breast cancer patients in the era of molecular oncology? A position paper of the Italian National Association of Breast Surgeons (ANISC)

Background: De-escalation of axillary surgery in breast cancer (BC) management began when sentinel lymph node biopsy (SLNB) replaced axillary lymph node dissection (ALND) as standard of care in patients with node-negative BC. The second step consolidated ALND omission in selected subgroups of BC patients with up to two macrometastases and recognized BC molecular and genomic implication in predicting prognosis and planning adjuvant treatment. Outcomes from the recent RxPONDER and monarchE trials have come to challenge the previous cut-off of two SLN in order to inform decisions on systemic therapies for hormone receptor-positive (HR+), human epidermal growth factor receptor type-2 (HER2) negative BC, as the criteria included a cut-off of respectively three and four SLNs. In view of the controversy that this may lift in surgical practice, the Italian National Association of Breast Surgeons (Associazione Nazionale Italiana Senologi Chirurghi, ANISC) reviewed data regarding the latest trials on this topic and proposes an implementation in clinical practice. Material and methods: We reviewed the available literature offering data on the pathological nodal status of cN0 breast cancer patients. Results: The rates of pN2 status in cN0 patients ranges from 3.5 % to 16 %; pre-surgical diagnostic definition of axillary lymph node status in cN0 patients by ultrasound could be useful to inform about a possible involvement of ≥4 lymph nodes in this specific sub-groups of women. Conclusions: The Italian National Association of Breast Surgeons (ANISC) considers that for HR + HER2-/cN0-pN1(sn) BC patients undergoing breast conserving treatment the preoperative workup should be optimized for a more detailed assessment of the axilla and the technique of SLNB should be optimized, if considered appropriate by the surgeon, not considering routine ALND always indicated to determine treatment recommendations according to criteria of eligibility to RxPONDER and monarch-E trials

Highly specialized Breast Centers did not experience delay of care during COVID-19 pandemic in Italy: the Senonetwork experience

The study aims to evaluate the performance of selected, high-volume, highly specialized, Italian Breast Centers at the time of COVID-19 pandemic (year 2020), compared to pre-pandemic time (year 2019), highlighting differences in terms of clinical presentation of breast cancer (BC) and therapeutic strategies

Trends in axillary lymph node dissection for early-stage breast cancer in Europe: Impact of evidence on practice

Background: Data from recently published trials have provided practice-changing recommendations for the surgical approach to the axilla in breast cancer. Patients with T1-2 lesions, treated with breast conservation, who have not received neoadjuvant chemotherapy and have 1\u20132 positive sentinel nodes (Z0011-criteria) may avoid axillary lymph node dissection (ALND). We aim to describe the dissemination of this practice in Europe over an extended period of time. Methods: Our source of data was the eusomaDB, a central data warehouse of prospectively collected information of the European Society of Breast Cancer Specialists (EUSOMA). We identified cases fulfilling Z0011-criteria from 2005 to 2016 from 34 European breast centers and report trends in ALND. Data derived from Germany, Italy, Belgium, Switzerland, Austria, and Netherlands. Results: 6671 patients fulfilled Z0011-criteria. Rates of ALND showed a statistically significant decrease from 2010 (89%) to 2011 (73%), reaching 46% in 2016 (p < 0.001). After multivariable analysis, factors associated with higher probability of ALND were earlier year of surgery, younger age, increasing tumor size and grade, and being operated in Italy (p < 0.001). The minimum and maximal rates of ALND in the most recent two-year period (2015\u20132016) were 0% and 83% in two centers located in different countries (p < 0.001). Conclusion: Our study demonstrates, a decrease in rates of ALND that started after year 2010 through the end of the study period. Wide differences were observed among centers and countries indicating the need to spread unified clinical guidelines in Europe to allow for homogeneous evidence-based practice patterns