Long-term Response to Vismodegib in a Patient with Gorlin-Goltz Syndrome: A Case Report and Review of Pathological Mechanisms Involved.

Nevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin-Goltz syndrome or Gorlin syndrome, is a rare multisystem disorder with an estimated prevalence of around 1 in 100,000 on average. Vismodegib, an oral smoothened (SMO) inhibitor that blocks the activation of the sonic hedgehog (SHH) pathway, is used in patients with NBCCS. We present an interesting case of a 38-year-old female with Gorlin-Goltz syndrome and her response to vismodegib therapy over two and a half years. She had an excellent initial response to vismodegib for a year during which all her skin basal cell carcinoma (BCC) lesions decreased in size considerably; her dentigerous cysts remained the same size. Though she continued therapy despite several side effects, this was only followed by tumor regrowth and the emergence of new BCC lesions in a more aggressive manner. We discussed the proposed mechanism of resistance to vismodegib (based on our case and literature review) along with its clinical implications. Our case highlights that vismodegib resistance might lead to progression of Gorlin syndrome to a more aggressive version, and points out the need to determine the optimal regimen (combining vismodegib with other agents) and optimal therapy duration (continuous treatment vs. discontinuation after best response) for treatment of NBCCS.

Nivolumab-Induced, Late-Onset, Steroid-Sensitive, High-Grade Pneumonitis and Durable Tumor Suppression in Metastatic Renal Cell Carcinoma: A Case Report.

Nivolumab, an antiprogrammed death-1 checkpoint inhibitor, has been approved for use in unresectable/metastatic renal cell carcinoma (RCC). Nivolumab-induced pneumonitis, a rare, but often severe and potentially life-threatening immune-related adverse event, has been reported, typically, early during the treatment. Due to its low incidence, more studies are needed to better elucidate this condition and its possible effects on cancer progression. We now present a 57-year-old Hispanic male patient with metastatic RCC-clear cell type who, after his 34th cycle of nivolumab (16 months after being on nivolumab), developed a late-onset, immune-related adverse event (IRAE) including a grade 3 pneumonitis, which resolved completely, clinically, and on serial lung imaging with steroids and drug discontinuation. His cancer remained stable with no progression for 18 months despite discontinuation of nivolumab which showed tumor progression resistance. This case report is aimed at providing further information regarding the rare phenomena of a late-onset IRAE, in particular, a grade 3 nivolumab-induced pneumonitis which also responded rapidly to treatment, as well as at discussing this immunotherapy's durable tumor suppressive effect and a possible associated factor to this phenomenon.

Esophageal Adenocarcinoma with Extensive Metastasis to Unexpected Sites: A Case Report.

BACKGROUND: Esophageal cancer (EC) with unexpected metastasis (UM) to unusual sites have been increasingly reported. EC with metastasis in general has a very high mortality and morbidity rate, and those with UM to unusual sites present another specific field that needs to be further studied in order to understand and manage the presentation. An extensive systematic review was recently completed regarding this field which identified characteristics and findings concerning patients with EC with UM sites. CASE PRESENTATION: We report a 61 year old Hispanic male who had an EC, adenocarcinoma subtype, with UM to an extensive number of sites such as the soft tissue of the cheek, subcutaneous forehead and scalp with penetration of the calvarium, occipital bone, base of tongue, neck muscles, paraspinal and iliopsoas musculature and, more typically, to an adrenal gland followed by a questionable new-onset finding of subcutaneous shoulder and flank nodules not initially identified by imaging. DISCUSSION/CONCLUSION: The case reports a patient who not only had EC with UM to unusual sites, but also to a considerable number. The patient correlated well in terms of clinical features identified by the systematic review of this particular field, but his case also showed a new finding, another unexpected metastasis site. This case also shows an example of why the type of imaging is important when dealing with UM sites. With this, we hope to further add to the data in this particular field and provide some opinion on this matter.

Septic Shock Predisposed by an Underlying Chronic Neutrophilic Leukemia with an Atypical Presentation; A Case Report.

BACKGROUND: Chronic neutrophilic leukemia (CNL) is an extremely rare myeloproliferative neoplasm (MPN). Due to the difficulty in its diagnosis, the diagnostic criterion was just recently revised in 2016. CNL is defined as: A clonal disorder with sustained primary neutrophilia, with normal neutrophil maturation, that does not meet other MPN criteria, as well as no identifiable mutations of the PDGFRA, PDGFRB or FGFR1 or PCM1-JAK2 genes, and, either, the presence of a CSF3R mutation, or if absent, the presence of sustained neutrophilia (> 3 months), splenomegaly and no other identifiable cause of reactive neutrophilia including the absence of a plasma cell neoplasm, or, if present, demonstration of myeloid cell clonality by cytogenetics. Only about 200 cases have been reported. CASE PRESENTATION: We report a 61-year-old Caucasian male patient who initially presented with unexplained leukocytosis. An outpatient work-up was planned to rule out a myeloproliferative disorder but the patient was acutely admitted for MRSA septic shock. The patient was stabilized prior bone marrow work-up and was then diagnosed with an atypical type of CNL (JAK2 positive, CSF3R negative). The patient refused further treatment due to social circumstances and requested palliative care instead. CONCLUSION: This case aims to present atypical findings of an extremely rare MPN. Even though a recent revision has been made to help in its diagnosis, atypical findings must still be considered. This, in turn, will help to further improve the current CNL diagnostic criteria.

Recurrent exposure to subclinical lipopolysaccharide increases mortality and induces cardiac fibrosis in mice.

BACKGROUND: Circulating subclinical lipopolysaccharide (LPS) occurs in health and disease. Ingesting high fatty meals increases LPS that cause metabolic endotoxemia. Subclinical LPS in periodontal disease may impair endothelial function. The heart may be targeted as cardiac cells express TLR4, the LPS receptor. It was hypothesized that recurrent exposure to subclinical LPS increases mortality and causes cardiac fibrosis. METHODS: C57Bl/6 mice were injected with intraperitoneal saline (control), low dose LPS (0.1 or 1 mg/kg), or moderate dose LPS (10 or 20 mg/kg), once a week for 3 months. Left ventricular (LV) function (echocardiography), hemodynamics (tail cuff pressure) and electrocardiograms (telemetry) were measured. Cardiac fibrosis was assessed by picrosirius red staining and LV expression of fibrosis related genes (QRT-PCR). Adult cardiac fibroblasts were isolated and exposed to LPS. RESULTS: LPS injections transiently increased heart rate and blood pressure (<6 hours) and mildly decreased LV function with full recovery by 24 hours. Mice tolerated weekly LPS for 2-3 months with no change in activity, appearance, appetite, weight, blood pressure, LV function, oximetry, or blood chemistries. Mortality increased after 60-90 days with moderate, but not low dose LPS. Arrhythmias occurred a few hours before death. LV collagen fraction area increased dose-dependently from 3.0±0.5% (SEM) in the saline control group, to 5.6±0.5% with low dose LPS and 9.7±0.9% with moderate dose LPS (P<0.05 moderate vs low dose LPS, and each LPS dose vs control). LPS increased LV expression of collagen Iα1, collagen IIIα1, MMP2, MMP9, TIMP1, periostin and IL-6 (P<0.05 moderate vs low dose LPS and vs control). LPS increased α-SMA immunostaining of myofibroblasts. LPS dose-dependently increased IL-6 in isolated adult cardiac fibroblasts. CONCLUSIONS: Recurrent exposure to subclinical LPS increases mortality and induces cardiac fibrosis.

DIDS prevents ischemic membrane degradation in cultured hippocampal neurons by inhibiting matrix metalloproteinase release.

During stroke, cells in the infarct core exhibit rapid failure of their permeability barriers, which releases ions and inflammatory molecules that are deleterious to nearby tissue (the penumbra). Plasma membrane degradation is key to penumbral spread and is mediated by matrix metalloproteinases (MMPs), which are released via vesicular exocytosis into the extracellular fluid in response to stress. DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid) preserves membrane integrity in neurons challenged with an in vitro ischemic penumbral mimic (ischemic solution: IS) and we asked whether this action was mediated via inhibition of MMP activity. In cultured murine hippocampal neurons challenged with IS, intracellular proMMP-2 and -9 expression increased 4-10 fold and extracellular latent and active MMP isoform expression increased 2-22 fold. MMP-mediated extracellular gelatinolytic activity increased ∼20-50 fold, causing detachment of 32.1±4.5% of cells from the matrix and extensive plasma membrane degradation (>60% of cells took up vital dyes and >60% of plasma membranes were fragmented or blebbed). DIDS abolished cellular detachment and membrane degradation in neurons and the pathology-induced extracellular expression of latent and active MMPs. DIDS similarly inhibited extracellular MMP expression and cellular detachment induced by the pro-apoptotic agent staurosporine or the general proteinase agonist 4-aminophenylmercuric acetate (APMA). Conversely, DIDS-treatment did not impair stress-induced intracellular proMMP production, nor the intracellular cleavage of proMMP-2 to the active form, suggesting DIDS interferes with the vesicular extrusion of MMPs rather than directly inhibiting proteinase expression or activation. In support of this hypothesis, an antagonist of the V-type vesicular ATPase also inhibited extracellular MMP expression to a similar degree as DIDS. In addition, in a proteinase-independent model of vesicular exocytosis, DIDS prevented stimulus-evoked release of von Willebrand Factor from human umbilical vein endothelial cells. We conclude that DIDS inhibits MMP exocytosis and through this mechanism preserves neuronal membrane integrity during pathological stress.

ChChd3, an inner mitochondrial membrane protein, is essential for maintaining crista integrity and mitochondrial function.

The mitochondrial inner membrane (IM) serves as the site for ATP production by hosting the oxidative phosphorylation complex machinery most notably on the crista membranes. Disruption of the crista structure has been implicated in a variety of cardiovascular and neurodegenerative diseases. Here, we characterize ChChd3, a previously identified PKA substrate of unknown function (Schauble, S., King, C. C., Darshi, M., Koller, A., Shah, K., and Taylor, S. S. (2007) J. Biol. Chem. 282, 14952-14959), and show that it is essential for maintaining crista integrity and mitochondrial function. In the mitochondria, ChChd3 is a peripheral protein of the IM facing the intermembrane space. RNAi knockdown of ChChd3 in HeLa cells resulted in fragmented mitochondria, reduced OPA1 protein levels and impaired fusion, and clustering of the mitochondria around the nucleus along with reduced growth rate. Both the oxygen consumption and glycolytic rates were severely restricted. Ultrastructural analysis of these cells revealed aberrant mitochondrial IM structures with fragmented and tubular cristae or loss of cristae, and reduced crista membrane. Additionally, the crista junction opening diameter was reduced to 50% suggesting remodeling of cristae in the absence of ChChd3. Analysis of the ChChd3-binding proteins revealed that ChChd3 interacts with the IM proteins mitofilin and OPA1, which regulate crista morphology, and the outer membrane protein Sam50, which regulates import and assembly of ß-barrel proteins on the outer membrane. Knockdown of ChChd3 led to almost complete loss of both mitofilin and Sam50 proteins and alterations in several mitochondrial proteins, suggesting that ChChd3 is a scaffolding protein that stabilizes protein complexes involved in maintaining crista architecture and protein import and is thus essential for maintaining mitochondrial structure and function.