Cas9-AAV6-engineered human mesenchymal stromal cells improved cutaneous wound healing in diabetic mice.

Human mesenchymal stromal cells (hMSCs) are a promising source for engineered cell-based therapies in which genetic engineering could enhance therapeutic efficacy and install novel cellular functions. Here, we describe an optimized Cas9-AAV6-based genome editing tool platform for site-specific mutagenesis and integration of up to more than 3 kilobases of exogenous DNA in the genome of hMSCs derived from the bone marrow, adipose tissue, and umbilical cord blood without altering their ex vivo characteristics. We generate safe harbor-integrated lines of engineered hMSCs and show that engineered luciferase-expressing hMSCs are transiently active in vivo in wound beds of db/db mice. Moreover, we generate PDGF-BB- and VEGFA-hypersecreting hMSC lines as short-term, local wound healing agents with superior therapeutic efficacy over wildtype hMSCs in the diabetic mouse model without replacing resident cells long-term. This study establishes a precise genetic engineering platform for genetic studies of hMSCs and development of engineered hMSC-based therapies.

Neurological adverse effects due to programmed death 1 (PD-1) inhibitors.

PURPOSE: PD-1 Immunotherapy is integral in treating multiple cancers, but has been associated with neurological adverse events (nAEs). Our study was aimed at identifying the clinical spectrum of nAEs associated with pembrolizumab and nivolumab. METHODS: We performed an IRB approved single-center retrospective cohort study on patients receiving either pembrolizumab or nivolumab. Patients that developed nAEs within 12 months of treatment were identified. Descriptive statistics were conducted, and differences between groups were analyzed by the Chi-square or t test method. RESULTS: In total, 649 patients were identified. Seventeen patients (2.6%) developed nAEs. Eight of those were on pembrolizumab and nine were on nivolumab. Average age was 62.1 years. Ten were males and 7 were females. Most patients had melanoma (6, 35.3%). Patients who developed nAEs more frequently had intracranial lesions at initiation of anti PD-1 therapy compared to those who did not develop nAEs (76.5% vs 27.8%; p-value < 0.001). Fifteen patients (88.2%) permanently stopped PD-1 therapy. In 8 patients, treatment termination resolved symptoms attributed to immune checkpoint blockade. The majority of patients developed grade 3 or 4 nAEs (10 patients, 58.8%), and required hospitalization (11 patients, 64.7%). Eight patients died for nAEs referable causes. CONCLUSION: Pembrolizumab and nivolumab are associated with the development of nAEs associated with increased risk of permanent discontinuation of treatment, hospitalization, and death. Melanoma patients might be at a particularly high risk of such side effects. Future studies are still required to better assess which patients benefit most from such therapies, while minimizing the risk of complications.

Long-term follow up data on difficult to treat intracranial arteriovenous malformations treated with the CyberKnife.

INTRODUCTION: The CyberKnife, a frameless, robotic, stereotactic device, has been developed to radiosurgically treat arteriovenous malformations (AVMs). While most AVMs are obliterated within two-to-three years, a subset remain recalcitrant; long-term data on these difficult to treat AVMs are limited in the neurosurgical literature. MATERIALS AND METHODS: A retrospective analysis of all patients who underwent CyberKnife treatment for intracranial AVMs at a single U.S. institution between 2002 and 2012, whose AVMs had failed to obliterate within 48 months or longer from the treatment start date, were eligible for inclusion. RESULTS: Eleven patients (9 AVMs; 7 males, 2 females) were followed for an average of 85.2 months (range 56.2-119.4). The median lesion size was 3.5 cm (range: 2.8-8.0 cm) and median Spetzler-Martin grade was 3 (range: 2-5). All AVMs were treated with one radiation dose (median prescribed dose was 18.0 Gy; median Dmax: 23.7 Gy). Six (66.7%) were obliterated in a median time of 84 months (range: 52-94 months), while 3 (33.3%) remained active after a median of 90.8 months (range 69.7-119.4). Transient, post-radiosurgery adverse radiation effects occurred in 5 (55.6%) cases. One (11.1%) patient had an acute hemorrhage from the AVM after radiosurgery. Four (44.4%) patients underwent repeat radiosurgery and/or embolization. Three of these lesions eventually obliterated, while 1 did not. CONCLUSION: The median time to obliteration was 84 months. Two-thirds of AVMs which persisted for over 4 years following initial radiosurgery treatment eventually obliterated. Transient post-radiosurgery adverse effects were common; delayed hemorrhages were rare in our case series.

Natural history of Rathke's cleft cysts: A retrospective analysis of a two centres experience.

OBJECTIVE: Rathke's cleft cyst (RCC) is a common sellar lesion which may cause visual impairment, hypopituitarism and headaches from mass effect. The natural history of these lesions is currently unclear. We investigated the natural history of RCCs and compared surgically treated patients with those treated conservatively. METHODS: We performed a retrospective cohort study of patients diagnosed with a RCC between 1996 and 2016 at Stanford University and Ospedale Maggiore Policlinico di Milano. RESULTS: Patients were divided into 2 cohorts: Group A, 72 subjects who underwent surgical resection of a symptomatic RCC, and Group B, 62 subjects managed conservatively. Compared to Group B, Group A subjects had larger RCCs (79% vs 22% had a largest diameter >10 mm, P < .001) and were more likely (41.5% vs 16%, P < .001) to present with hypopituitarism and diabetes insipidus (DI) (18% vs 1.6%, P = .002). In Group A, after a mean follow-up of 53.7 months, 12.5% of patients had recurrence and a second surgery. After surgery, 35% of patients recovered pituitary function. Hyperprolactinemia (26.6%) and hypogonadism (66.6%) resolved more commonly that did DI (20.1%). New pituitary deficits appeared in 16.6% of patients after surgery. In Group B, with a mean follow-up of 41 months, only 6.4% had cyst enlargement, none underwent surgery, and none developed a pituitary deficit. CONCLUSION: Our data offer guidance in decision-making regarding the management of RCC patients and confirm the safety of conservative treatment in asymptomatic patients.

CyberKnife robotic radiosurgery in the multimodal management of acromegaly patients with invasive macroadenoma: a single center's experience.

Surgery is the primary treatment for acromegaly. However, surgery may not be curative of some tumors, particularly invasive macroadenomas. Adjuvant radiation, specifically robotic stereotactic radiosurgery (rSRS), may improve the endocrine outcome. We retrospectively reviewed hormonal and radiological data of 22 acromegalic patients with invasive macroadenomas treated with rSRS at Stanford University Medical Center between 2000 and 2016. Prior to treatment, the tumor's median maximal diameter was 19 mm (2.5-50 mm). Cavernous sinus invasion occurred in 19 patients (86.3%) and compression of the optic chiasm in 2 (9.0%). At last follow up, with an average follow up of 43.2 months, all patients had a reduction in their IGF-1 levels (median IGF-1% upper limit of normal (ULN) baseline: 136% vs last follow up: 97%; p = 0.05); 9 patients (40.9%) were cured, and 4 (18.1%) others demonstrated biochemical control of acromegaly. The median time to cure was 50 months and the mean interval to cure or biochemical control was 30.3 months (± 24 months, range 6-84 months). Hypopituitarism was present in 8 patients (36.3%) and new pituitary deficits occurred in 6 patients with a median latency of 31.6 ± 14.5 months. At final radiologic follow-up, 3 tumors (13.6%) were smaller and 19 were stable in size. The mean biologically effective dose (BED) was higher in subjects cured compared to those with persistent disease, 163 Gy3 (± 47) versus 111 Gy3 (± 43), respectively (p = 0.01). No patient suffered visual deterioration. Robotic SRS is a safe and effective treatment for acromegaly: radiation-induced visual complications and hypopituitarism is rare.

CyberKnife Radiosurgery in the Multimodal Management of Patients with Cushing Disease.

BACKGROUND: Surgery is the primary treatment for Cushing disease. When surgery is unsuccessful in normalizing hypercortisolism, adjuvant radiation, such as stereotactic radiosurgery, may be useful to improve biochemical control. METHODS: This retrospective study included a cohort of consecutive patients treated with CyberKnife (CK) radiosurgery for active Cushing disease at Stanford Hospital and Clinics. RESULTS: As first-line treatment, all patients underwent transsphenoidal surgery with histologic demonstration of an adrenocorticotropic hormone-producing pituitary adenoma. CK was performed as adjuvant therapy for persistent or recurrent disease. The median time between surgery and CK was 14 ± 34 months. Before CK, median maximal diameter of tumors was 9 mm (range, 7-32 mm), with cavernous sinus invasion in all patients (100%) and abutment of the optic chiasm in 1 patient (14.2%). With an average follow-up of 55.4 months, normalization of hypercortisolism was achieved in 4 patients (57.1%): 2 patients (28.5%) achieved normalization of the hypothalamic-pituitary-adrenal axis without glucocorticoid replacement, and 2 patients developed hypoadrenalism (28.5%). The median time to biochemical remission was 12.5 months. Hypopituitarism occurred in only 1 patient (14.2%), and no patients had visual complications. Time between surgery and radiotherapy of <14 months was associated with a significantly improved biochemical remission rate (P = 0.02). CONCLUSIONS: In a cohort of patients with Cushing disease, we demonstrate that CK is an effective treatment with rare complications.